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Ali S, Stanley J, Davis S, Keenan N, Scheffer IE, Sadleir LG. Epidemiology of Treated Epilepsy in New Zealand Children: A Focus on Ethnicity. Neurology 2021; 97:e1933-e1941. [PMID: 34504020 DOI: 10.1212/wnl.0000000000012784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 09/03/2021] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND AND OBJECTIVES To determine the period prevalence and incidence of treated epilepsy in a New Zealand pediatric cohort with a focus on ethnicity and socioeconomic status. METHODS This was a retrospective cohort study. The New Zealand Pharmaceutical Collection database was searched for individuals ≤18 years of age dispensed an antiseizure medication (ASM) in 2015 from areas capturing 48% of the New Zealand pediatric population. Medical records of identified cases were reviewed to ascertain the indication for the ASM prescription. Population data were derived from the New Zealand 2013 Census. RESULTS A total of 3,557 ASMs were prescribed during 2015 in 2,594 children, of whom 1,717 (66%) children had epilepsy. An indication for prescription was ascertained for 3,332/3,557 (94%) ASMs. The period prevalence of treated epilepsy was 3.4 per 1,000 children. Children in the most deprived areas had 1.9 times the rate of treated epilepsy (95% confidence interval [CI] 1.6-2.2) as those from the least deprived areas. Prevalence was similar for most ethnic groups (European/other: 3.7, 95% CI 3.4-3.9; Pacific Peoples: 3.6, 95% CI 3.2-4.1; Māori: 3.4, 95% CI 3.1-3.8) apart from Asians, who had a lower prevalence of 2.3 per 1,000 (95% CI 2.0-2.6). However, when adjusted for socioeconomic deprivation, the prevalence of epilepsy was highest in European and similar in Māori, Pacific, and Asian children. DISCUSSION This is the largest pediatric epidemiology epilepsy study where diagnosis of epilepsy was confirmed by case review. This is the first study to provide epidemiologic information for pediatric epilepsy in Māori and Pacific children.
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Affiliation(s)
- Shayma Ali
- From the Departments of Pediatrics and Child Health (S.A., S.D., N.K., L.G.S.) and Public Health (J.S.), University of Otago, Wellington, New Zealand; and the Departments of Medicine and Pediatrics (I.S.), Austin Health and Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, University of Melbourne, Australia
| | - James Stanley
- From the Departments of Pediatrics and Child Health (S.A., S.D., N.K., L.G.S.) and Public Health (J.S.), University of Otago, Wellington, New Zealand; and the Departments of Medicine and Pediatrics (I.S.), Austin Health and Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, University of Melbourne, Australia
| | - Suzanne Davis
- From the Departments of Pediatrics and Child Health (S.A., S.D., N.K., L.G.S.) and Public Health (J.S.), University of Otago, Wellington, New Zealand; and the Departments of Medicine and Pediatrics (I.S.), Austin Health and Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, University of Melbourne, Australia
| | - Ngaire Keenan
- From the Departments of Pediatrics and Child Health (S.A., S.D., N.K., L.G.S.) and Public Health (J.S.), University of Otago, Wellington, New Zealand; and the Departments of Medicine and Pediatrics (I.S.), Austin Health and Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, University of Melbourne, Australia
| | - Ingrid Eileen Scheffer
- From the Departments of Pediatrics and Child Health (S.A., S.D., N.K., L.G.S.) and Public Health (J.S.), University of Otago, Wellington, New Zealand; and the Departments of Medicine and Pediatrics (I.S.), Austin Health and Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, University of Melbourne, Australia.
| | - Lynette Grant Sadleir
- From the Departments of Pediatrics and Child Health (S.A., S.D., N.K., L.G.S.) and Public Health (J.S.), University of Otago, Wellington, New Zealand; and the Departments of Medicine and Pediatrics (I.S.), Austin Health and Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, University of Melbourne, Australia
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Soteros BM, Sia GM. Complement and microglia dependent synapse elimination in brain development. WIREs Mech Dis 2021; 14:e1545. [PMID: 34738335 PMCID: PMC9066608 DOI: 10.1002/wsbm.1545] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 10/10/2021] [Accepted: 10/12/2021] [Indexed: 01/31/2023]
Abstract
Synapse elimination, also known as synaptic pruning, is a critical step in the maturation of neural circuits during brain development. Mounting evidence indicates that the complement cascade of the innate immune system plays an important role in synapse elimination. Studies indicate that excess synapses during development are opsonized by complement proteins and subsequently phagocytosed by microglia which expresses complement receptors. The process is regulated by diverse molecular signals, including complement inhibitors that affect the activation of complement, as well as signals that affect microglial recruitment and activation. These signals may promote or inhibit the removal of specific sets of synapses during development. The complement-microglia system has also been implicated in the pathogenesis of several developmental brain disorders, suggesting that the dysregulation of mechanisms of synapse pruning may underlie the specific circuitry defects in these diseases. Here, we review the latest evidence on the molecular and cellular mechanisms of complement-dependent and microglia-dependent synapse elimination during brain development, and highlight the potential of this system as a therapeutic target for developmental brain disorders. This article is categorized under: Neurological Diseases > Molecular and Cellular Physiology Neurological Diseases > Stem Cells and Development Immune System Diseases > Molecular and Cellular Physiology.
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Affiliation(s)
- Breeanne M Soteros
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Gek Ming Sia
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
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Abstract
With the advent of next generation sequencing technology there has been a spurt of papers on genetics in epilepsy in children. Genetic testing has now become an essential part of clinical practice in epilepsy. It helps in reaching an etiological diagnosis, providing prognostic information, guiding therapy precisely indicated for the patient and avoiding drugs that may worsen the seizures. Once the pathogenic variant has been found, this enables determining and counseling the risk of recurrence to the patient and other relatives at risk. It also makes available different reproductive options such as prenatal diagnosis or pre-implantation diagnosis. The authors describe the benefits, the clinical situations that require genetic testing, the types of genetic tests that are available, and how to choose the appropriate test and their likely yields. Genetic counseling, both pre- and post-test that should be provided is described briefly. Two useful tables are included that depict the therapy for variants in different epilepsy genes.
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Ye Z, Bennett MF, Bahlo M, Scheffer IE, Berkovic SF, Perucca P, Hildebrand MS. Cutting edge approaches to detecting brain mosaicism associated with common focal epilepsies: implications for diagnosis and potential therapies. Expert Rev Neurother 2021; 21:1309-1316. [PMID: 34519595 DOI: 10.1080/14737175.2021.1981288] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Mosaic variants arising in brain tissue are increasingly being recognized as a hidden cause of focal epilepsy. This knowledge gain has been driven by new, highly sensitive genetic technologies and genome-wide analysis of brain tissue from surgical resection or autopsy in a small proportion of patients with focal epilepsy. Recently reported novel strategies to detect mosaic variants limited to brain have exploited trace brain DNA obtained from cerebrospinal fluid liquid biopsies or stereo-electroencephalography electrodes. AREAS COVERED The authors review the data on these innovative approaches published in PubMed before 12 June 2021, discuss the challenges associated with their application, and describe how they are likely to improve detection of mosaic variants to provide new molecular diagnoses and therapeutic targets for focal epilepsy, with potential utility in other nonmalignant neurological disorders. EXPERT OPINION These cutting-edge approaches may reveal the hidden genetic etiology of focal epilepsies and provide guidance for precision medicine.
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Affiliation(s)
- Zimeng Ye
- Department of Medicine (Austin Health), Epilepsy Research Centre, University of Melbourne, Heidelberg, Australia
| | - Mark F Bennett
- Department of Medicine (Austin Health), Epilepsy Research Centre, University of Melbourne, Heidelberg, Australia.,Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - Melanie Bahlo
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - Ingrid E Scheffer
- Department of Medicine (Austin Health), Epilepsy Research Centre, University of Melbourne, Heidelberg, Australia.,Neuroscience Research Group, Murdoch Children's Research Institute, Parkville, Australia.,Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Australia.,Department of Neurology, Comprehensive Epilepsy Program, Austin Health, Heidelberg, Australia
| | - Samuel F Berkovic
- Department of Medicine (Austin Health), Epilepsy Research Centre, University of Melbourne, Heidelberg, Australia.,Department of Neurology, Comprehensive Epilepsy Program, Austin Health, Heidelberg, Australia
| | - Piero Perucca
- Department of Medicine (Austin Health), Epilepsy Research Centre, University of Melbourne, Heidelberg, Australia.,Department of Neurology, Comprehensive Epilepsy Program, Austin Health, Heidelberg, Australia.,Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia.,Department of Neurology, Alfred Health, Melbourne, Australia.,Department of Neurology, The Royal Melbourne Hospital, Parkville, Australia
| | - Michael S Hildebrand
- Department of Medicine (Austin Health), Epilepsy Research Centre, University of Melbourne, Heidelberg, Australia.,Neuroscience Research Group, Murdoch Children's Research Institute, Parkville, Australia
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Zhang L, Wang Y. Gene therapy in epilepsy. Biomed Pharmacother 2021; 143:112075. [PMID: 34488082 DOI: 10.1016/j.biopha.2021.112075] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 08/11/2021] [Accepted: 08/17/2021] [Indexed: 01/15/2023] Open
Abstract
Gene therapy may constitute a promising alternative to conventional pharmacological tools and surgeries for epilepsy. For primary epilepsy, a single variant leading to a significant effect is relatively rare, while other forms are considered complex in inheritances with multiple susceptible mutations and impacts from the environment. Gene therapy in preclinical models of epilepsy has attempted to perform antiepileptogenic, anticonvulsant, or disease-modifying effects during epileptogenesis or after establishing the disease. Creating gene vectors tailored for different situations is the key to expanding gene therapy, and choosing the appropriate therapeutic target remains another fundamental problem. A variety of treatment strategies, from overexpressing inhibitory neuropeptides to modulating the expression of neurotransmitters or ion channels, have been tested in animal models. Additionally, emerging new approaches of optogenetics and chemogenetics, as well as genome-editing tools will further boost the prosperity of gene therapy. This review summarizes the experience obtained to date and discusses the challenges and opportunities in clinical translations.
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Affiliation(s)
- Lu Zhang
- Department of Neurology at Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Yuping Wang
- Beijing Key Laboratory of Neuromodulation, Capital Medical University, Beijing, China; Center of Epilepsy, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.
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Turkdogan D, Turkyilmaz A, Sager G, Ozturk G, Unver O, Say M. Chromosomal microarray and exome sequencing in unexplained early infantile epileptic encephalopathies in a highly consanguineous population. Int J Neurosci 2021:1-18. [PMID: 34380004 DOI: 10.1080/00207454.2021.1967349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
AIM To identify genetic causes for early infantile epileptic encephalopathies (EIEE) in Turkish children with mostly consanguineous parents. METHODS In a selected EIEE group (N = 59) based on results of nongenetic and initial genetic testing with unexplained etiology, 49 patients underwent array-based comparative genomic hybridization (aCGH) and 49 patients underwent whole exome sequencing (WES) including 39 with negative aCGH results and 10 with WES-only. RESULTS Diagnostic yield of aCGH and WES for pathogenic or likely pathogenic variants was 14.3% and 38.8%, respectively. Including de novo variants of uncertain significance linked to compatible phenotypes, increased the diagnostic yield of WES to 61.2%. Out of 38 positive variants, 18 (47.4%) were novel and 16 (42.1%) were de novo. Twenty-one (56.8%) patients had recessive variants inherited from mostly consanguineous healthy parents (85.7%). Fourteen (37.8%) of patients with diagnostic results had positive variants in established EIEE genes. Seizures started during neonatal period in 32.4% patients. Posture or movement disorders were comorbid with EIEE in 40.5% of diagnosed patients. We identified treatable metabolic disorders in 8.1% of patients and pathogenic variants in genes which support using targeted medicine in 19% of patients. CONCLUSIONS Detailed electro-clinical phenotyping led to expansion of some of the known phenotypes with non-neurological and neurological findings in addition to seizures, as well as suggestion of candidate genes (SEC24B, SLC16A2 and PRICKLE2) and a copy number variant (microduplication of Xp21.1p11.4). The high ratio of recessive inheritance could be important for family counseling.
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Affiliation(s)
- Dilsad Turkdogan
- Medical Faculty, Department of Pediatric Neurology, Marmara University, Pendik, Istanbul, Turkey
| | - Ayberk Turkyilmaz
- Medical Faculty, Department of Medical Genetics, Marmara University, Pendik, Istanbul, Turkey
| | - Gunes Sager
- Medical Faculty, Department of Pediatric Neurology, Marmara University, Pendik, Istanbul, Turkey
| | - Gulten Ozturk
- Medical Faculty, Department of Pediatric Neurology, Marmara University, Pendik, Istanbul, Turkey
| | - Olcay Unver
- Medical Faculty, Department of Pediatric Neurology, Marmara University, Pendik, Istanbul, Turkey
| | - Merve Say
- Bioinformatics, Private Practice, Kadıkoy, Istanbul, Turkey
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Bleakley LE, McKenzie CE, Soh MS, Forster IC, Pinares-Garcia P, Sedo A, Kathirvel A, Churilov L, Jancovski N, Maljevic S, Berkovic SF, Scheffer IE, Petrou S, Santoro B, Reid CA. Cation leak underlies neuronal excitability in an HCN1 developmental and epileptic encephalopathy. Brain 2021; 144:2060-2073. [PMID: 33822003 PMCID: PMC8370418 DOI: 10.1093/brain/awab145] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 02/12/2021] [Accepted: 03/20/2021] [Indexed: 01/09/2023] Open
Abstract
Pathogenic variants in HCN1 are associated with developmental and epileptic encephalopathies. The recurrent de novo HCN1 M305L pathogenic variant is associated with severe developmental impairment and drug-resistant epilepsy. We engineered the homologue Hcn1 M294L heterozygous knock-in (Hcn1M294L) mouse to explore the disease mechanism underlying an HCN1 developmental and epileptic encephalopathy. The Hcn1M294L mouse recapitulated the phenotypic features of patients with the HCN1 M305L variant, including spontaneous seizures and a learning deficit. Active epileptiform spiking on the electrocorticogram and morphological markers typical of rodent seizure models were observed in the Hcn1M294L mouse. Lamotrigine exacerbated seizures and increased spiking, whereas sodium valproate reduced spiking, mirroring drug responses reported in a patient with this variant. Functional analysis in Xenopus laevis oocytes and layer V somatosensory cortical pyramidal neurons in ex vivo tissue revealed a loss of voltage dependence for the disease variant resulting in a constitutively open channel that allowed for cation 'leak' at depolarized membrane potentials. Consequently, Hcn1M294L layer V somatosensory cortical pyramidal neurons were significantly depolarized at rest. These neurons adapted through a depolarizing shift in action potential threshold. Despite this compensation, layer V somatosensory cortical pyramidal neurons fired action potentials more readily from rest. A similar depolarized resting potential and left-shift in rheobase was observed for CA1 hippocampal pyramidal neurons. The Hcn1M294L mouse provides insight into the pathological mechanisms underlying hyperexcitability in HCN1 developmental and epileptic encephalopathy, as well as being a preclinical model with strong construct and face validity, on which potential treatments can be tested.
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Affiliation(s)
- Lauren E Bleakley
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Chaseley E McKenzie
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Ming S Soh
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Ian C Forster
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Paulo Pinares-Garcia
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Alicia Sedo
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Anirudh Kathirvel
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Leonid Churilov
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
- Melbourne Medical School, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Nikola Jancovski
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Snezana Maljevic
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Samuel F Berkovic
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Heidelberg, Victoria 3084, Australia
| | - Ingrid E Scheffer
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Heidelberg, Victoria 3084, Australia
- Department of Paediatrics, University of Melbourne, Royal Children’s Hospital, Parkville, Victoria 3052, Australia
| | - Steven Petrou
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Bina Santoro
- Department of Neuroscience, The Kavli Institute for Brain Science, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Christopher A Reid
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Heidelberg, Victoria 3084, Australia
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Epilepsy Syndromes in the First Year of Life and Usefulness of Genetic Testing for Precision Therapy. Genes (Basel) 2021; 12:genes12071051. [PMID: 34356067 PMCID: PMC8307222 DOI: 10.3390/genes12071051] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/23/2021] [Accepted: 07/05/2021] [Indexed: 12/18/2022] Open
Abstract
The high pace of gene discovery has resulted in thrilling advances in the field of epilepsy genetics. Clinical testing with comprehensive gene panels, exomes, or genomes are now increasingly available and have led to a significant higher diagnostic yield in early-onset epilepsies and enabled precision medicine approaches. These have been instrumental in providing insights into the pathophysiology of both early-onset benign and self-limited syndromes and devastating developmental and epileptic encephalopathies (DEEs). Genetic heterogeneity is seen in many epilepsy syndromes such as West syndrome and epilepsy of infancy with migrating focal seizures (EIMFS), indicating that two or more genetic loci produce the same or similar phenotypes. At the same time, some genes such as SCN2A can be associated with a wide range of epilepsy syndromes ranging from self-limited familial neonatal epilepsy at the mild end to Ohtahara syndrome, EIFMS, West syndrome, Lennox–Gastaut syndrome, or unclassifiable DEEs at the severe end of the spectrum. The aim of this study was to review the clinical and genetic heterogeneity associated with epilepsy syndromes starting in the first year of life including: Self-limited familial neonatal, neonatal-infantile or infantile epilepsies, genetic epilepsy with febrile seizures plus spectrum, myoclonic epilepsy in infancy, Ohtahara syndrome, early myoclonic encephalopathy, West syndrome, Dravet syndrome, EIMFS, and unclassifiable DEEs. We also elaborate on the advantages and pitfalls of genetic testing in such conditions. Finally, we describe how a genetic diagnosis can potentially enable precision therapy in monogenic epilepsies and emphasize that early genetic testing is a cornerstone for such therapeutic strategies.
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Clemens B, Emri M, Csaba Aranyi S, Fekete I, Fekete K. Resting-state EEG theta activity reflects degree of genetic determination of the major epilepsy syndromes. Clin Neurophysiol 2021; 132:2232-2239. [PMID: 34315064 DOI: 10.1016/j.clinph.2021.06.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 06/12/2021] [Accepted: 06/15/2021] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To explore relationship between EEG theta activity and clinical data that imply the degree of genetic determination of epilepsy. METHODS Clinical data of interest were epilepsy diagnosis and positive / negative family history of epilepsy. Study groups were: idiopathic generalized epilepsy (IGE), focal epilepsy (FE); FE of unknown etiology (FEUNK), FE of postnatal-acquired etiology (FEPA); all patients with positive / negative family history of epilepsy (FAPALL, FANALL, respectively), disregarding of the syndrome; FAP patients with 1st degree affected relative (FAP1) and those with 2nd degree epileptic relative only (FAP2). Quantitative EEG analysis assessed amount of theta (3.5-7.0 Hz) activity in 180 seconds of artifact-free waking EEG background activity for each patient and group. Group comparison was carried out by nonparametric statistics. RESULTS Differences of theta activity were: FAPALL > FANALL (p = 0.01); FAP1 > FAP2 (p = 0.2752). IGE > FE (p = 0.02); FEUNK > FEPA (p = 0.07). CONCLUSIONS This was the first attempt to explore and quantitatively ascertain relationship between an EEG variable and clinical data that imply greater or lesser degree of genetic determination in epilepsy. SIGNIFICANCE Theta activity is endophenotype that bridges the gap between epilepsy susceptibility genes and clinical phenotypes. Amount of theta activity is indicative of degree of genetic determination of the epilepsies.
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Affiliation(s)
- Béla Clemens
- Kenézy Gyula University Hospital, Neurology Division, University of Debrecen, Hungary.
| | - Miklós Emri
- Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of Debrecen, Hungary
| | - Sándor Csaba Aranyi
- Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of Debrecen, Hungary
| | - István Fekete
- University of Debrecen, Faculty of Medicine, Department of Neurology, Hungary
| | - Klára Fekete
- University of Debrecen, Faculty of Medicine, Department of Neurology, Hungary
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Videira G, Gabriel D, Freitas J, Samões R, Chorão R, Lopes J, Ramalheira J, Lemos C, Leal B, da Silva AM, Chaves J. Female preponderance in genetic generalized epilepsies. Seizure 2021; 91:167-171. [PMID: 34171625 DOI: 10.1016/j.seizure.2021.06.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/26/2021] [Accepted: 06/10/2021] [Indexed: 10/21/2022] Open
Abstract
INTRODUCTION Epilepsy is more prevalent in men but Genetic Generalized Epilepsies (GGE) seem to be more common in women. A predominant maternal inheritance has been previously described in GGE. Our objective was to determine sex and inheritance patterns in a GGE population compared to mesial temporal lobe epilepsy with hippocampal sclerosis (MTLEHS). METHODS We performed a prospective observational study including adult GGE and MTLEHS patients followed up at a tertiary epilepsy center from January 2016 to December 2019. Patients' familial history was obtained by a detailed questionnaire. Clinical and demographic data was retrieved from clinical notes. RESULTS A cohort of 641 patients, 403 with GGE and 238 with MTLEHS, was analyzed. GGE was more common in women than MTLEHS (58.8% vs 44.5%, OR=1.63, p = 0.004). Compared to MTLEHS patients, more GGE patients had familial history of epilepsy (45.4% vs 25.2%; p<0.001). The GGE group had a higher percentage of female relatives with epilepsy (55% vs 37%; p = 0.006). The prevalence of maternal inheritance was not different between GGE and MTLEHS groups (62.9% vs 57.7%; p = 0.596). Photosensitivity was more common in females than in males (44.7% vs 34.3%, p = 0.036). CONCLUSION There is a female preponderance in GGE when compared to MTLEHS, as both GGE patients and their affected relatives are more frequently women. The prevalence of maternal inheritance was not higher in GGE than in MTLEHS.
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Affiliation(s)
- Gonçalo Videira
- Neurology Department, Centro Hospitalar Universitário do Porto, Portugal.
| | - Denis Gabriel
- Neurology Department, Centro Hospitalar Universitário do Porto, Portugal
| | - Joel Freitas
- Neurophysiology Department, Centro Hospitalar Universitário do Porto, Portugal
| | - Raquel Samões
- Neurology Department, Centro Hospitalar Universitário do Porto, Portugal
| | - Rui Chorão
- Neurophysiology Department, Centro Hospitalar Universitário do Porto, Portugal
| | - João Lopes
- Neurophysiology Department, Centro Hospitalar Universitário do Porto, Portugal
| | - João Ramalheira
- Neurophysiology Department, Centro Hospitalar Universitário do Porto, Portugal
| | - Carolina Lemos
- UnIGENe, IBMC - Institute for Molecular and Cell Biology, i3S - Instituto de Investigação e Inovação em Saúde, University of Porto, Portugal; Abel Salazar Biomedical Sciences Institute, University of Porto, Portugal
| | - Bárbara Leal
- Immunogenetics Laboratory, Pathology and Molecular Immunology Department, Abel Salazar Biomedical Sciences Institute, University of Porto, Portugal; Biomedical Investigation Multidisciplinary Unit, Abel Salazar Biomedical Sciences Institute, University of Porto, Portugal
| | - António Martins da Silva
- Neurophysiology Department, Centro Hospitalar Universitário do Porto, Portugal; Biomedical Investigation Multidisciplinary Unit, Abel Salazar Biomedical Sciences Institute, University of Porto, Portugal
| | - João Chaves
- Neurology Department, Centro Hospitalar Universitário do Porto, Portugal; Biomedical Investigation Multidisciplinary Unit, Abel Salazar Biomedical Sciences Institute, University of Porto, Portugal
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Yu N, Lin XJ, Di Q. How to Find Candidate Drug-targets for Antiepileptogenic Therapy? Curr Neuropharmacol 2021; 18:624-635. [PMID: 31989901 PMCID: PMC7457424 DOI: 10.2174/1570159x18666200128124338] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/10/2019] [Accepted: 01/27/2020] [Indexed: 11/22/2022] Open
Abstract
Although over 25 antiepileptic drugs (AEDs) have become currently available for clinical use, the incidence of epilepsy worldwide and the proportions of drug-resistant epilepsy among them are not significantly reduced during the past decades. Traditional screens for AEDs have been mainly focused on their anti-ictogenic roles, and their efficacies primarily depend on suppressing neuronal excitability or enhancing inhibitory neuronal activity, almost without the influence on the epileptogenesis or with inconsistent results from different studies. Epileptogenesis refers to the pathological process of a brain from its normal status to the alterations with the continuous prone of unprovoked spontaneous seizures after brain insults, such as stroke, traumatic brain injury, CNS infectious, and autoimmune disorders, and even some specific inherited conditions. Recently growing experimental and clinical studies have discovered the underlying mechanisms for epileptogenesis, which are multi-aspect and multistep. These findings provide us a number of interesting sites for antiepileptogenic drugs (AEGDs). AEGDs have been evidenced as significantly roles of postponing or completely blocking the development of epilepsy in experimental models. The present review will introduce potential novel candidate drug-targets for AEGDs based on the published studies.
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Affiliation(s)
- Nian Yu
- Department of Neurology, The Affiliated Nanjing Brain Hospital of Nanjing Medical University, 210029, Nanjing, China
| | - Xing-Jian Lin
- Department of Neurology, The Affiliated Nanjing Brain Hospital of Nanjing Medical University, 210029, Nanjing, China
| | - Qing Di
- Department of Neurology, The Affiliated Nanjing Brain Hospital of Nanjing Medical University, 210029, Nanjing, China
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Stevelink R, Luykx JJ, Lin BD, Leu C, Lal D, Smith AW, Schijven D, Carpay JA, Rademaker K, Rodrigues Baldez RA, Devinsky O, Braun KPJ, Jansen FE, Smit DJA, Koeleman BPC. Shared genetic basis between genetic generalized epilepsy and background electroencephalographic oscillations. Epilepsia 2021; 62:1518-1527. [PMID: 34002374 PMCID: PMC8672363 DOI: 10.1111/epi.16922] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Indexed: 11/29/2022]
Abstract
Objective Paroxysmal epileptiform abnormalities on electroencephalography (EEG) are the hallmark of epilepsies, but it is uncertain to what extent epilepsy and background EEG oscillations share neurobiological underpinnings. Here, we aimed to assess the genetic correlation between epilepsy and background EEG oscillations. Methods Confounding factors, including the heterogeneous etiology of epilepsies and medication effects, hamper studies on background brain activity in people with epilepsy. To overcome this limitation, we compared genetic data from a genome‐wide association study (GWAS) on epilepsy (n = 12 803 people with epilepsy and 24 218 controls) with that from a GWAS on background EEG (n = 8425 subjects without epilepsy), in which background EEG oscillation power was quantified in four different frequency bands: alpha, beta, delta, and theta. We replicated our findings in an independent epilepsy replication dataset (n = 4851 people with epilepsy and 20 428 controls). To assess the genetic overlap between these phenotypes, we performed genetic correlation analyses using linkage disequilibrium score regression, polygenic risk scores, and Mendelian randomization analyses. Results Our analyses show strong genetic correlations of genetic generalized epilepsy (GGE) with background EEG oscillations, primarily in the beta frequency band. Furthermore, we show that subjects with higher beta and theta polygenic risk scores have a significantly higher risk of having generalized epilepsy. Mendelian randomization analyses suggest a causal effect of GGE genetic liability on beta oscillations. Significance Our results point to shared biological mechanisms underlying background EEG oscillations and the susceptibility for GGE, opening avenues to investigate the clinical utility of background EEG oscillations in the diagnostic workup of epilepsy.
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Affiliation(s)
- Remi Stevelink
- Department of Genetics, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.,Department of Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Jurjen J Luykx
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.,Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.,GGNet Mental Health, Apeldoorn, the Netherlands
| | - Bochao D Lin
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.,Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Costin Leu
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachussets, USA
| | - Dennis Lal
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachussets, USA
| | - Alexander W Smith
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachussets, USA
| | - Dick Schijven
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.,Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Johannes A Carpay
- Department of Neurology, Tergooi Hospital, Hilversum, the Netherlands
| | - Koen Rademaker
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Roiza A Rodrigues Baldez
- Clinical Research Laboratory on Neuroinfectious Diseases, Evandro Chagas Clinical Research Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Orrin Devinsky
- Comprehensive Epilepsy Center, New York University School of Medicine, New York, New York, USA
| | - Kees P J Braun
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Floor E Jansen
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Dirk J A Smit
- Psychiatry Department, Amsterdam Neuroscience, Amsterdam Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Bobby P C Koeleman
- Department of Genetics, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
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63
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Hasırcı Bayır BR, Tutkavul K, Eser M, Baykan B. Epilepsy in patients with familial hemiplegic migraine. Seizure 2021; 88:87-94. [PMID: 33839563 DOI: 10.1016/j.seizure.2021.03.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 03/26/2021] [Accepted: 03/28/2021] [Indexed: 02/03/2023] Open
Abstract
OBJECTIVE The coexistence of epilepsy in familial hemiplegic migraine (FHM) has not been reviewed systematically. We investigated the associations of epilepsy in patients with FHM with CACNA1A, ATP1A2, SCN1A or PRRT2 mutations along with clinical and genetic data. MATERIALS AND METHODS We performed a search in the PubMed bibliographic database and the Cochrane Library was screened for eligible studies, from April 1997 to December 2020. Additionally, Online Mendelian Inheritance in Man (OMIM) was searched for mutations in the CACNA1A, ATP1A2, SCN1A and PRRT2 genes. Brief reports, letters, and original articles about FHM and epilepsy were included in the review if their mutations and clinical course of diseases were identified. RESULTS Of the included patients with FHM whose information could be accessed, there were 28 families and 195 individuals, 78 of whom had epilepsy; 30 patients had focal epilepsy and 30 patients had generalized epilepsy. All mutations except ATP1A2, which could not be evaluated due to insufficient data, revealed first epilepsy then HM. In 60 patients for whom the epilepsy prognosis was evaluated, only 3.5% of patients were drug-resistant, and the remainder had a self-limited course or responded to anti-epileptic drug treatment. CONCLUSION Mutations in all three and possibly four FHM genes can cause epilepsy. Contrary to our expectations, the well-known epilepsy gene SCN1A mutations are not the leading cause; the highest number of cases associated with epilepsy belongs to the ATP1A2 mutation. Drug-resistant forms of epilepsy are rare in all FHM mutations, and this information is important for counseling patients.
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Affiliation(s)
- Buse Rahime Hasırcı Bayır
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey; Department of Neurology, Haydarpaşa Numune Research and Training Hospital, Istanbul, Turkey.
| | - Kemal Tutkavul
- Department of Neurology, Haydarpaşa Numune Research and Training Hospital, Istanbul, Turkey.
| | - Metin Eser
- Department of Medical Genetics, Ümraniye Research and Training Hospital, Istanbul, Turkey.
| | - Betül Baykan
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey; Neuroscience Department, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey.
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64
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Lo AC, Rajan N, Gastaldo D, Telley L, Hilal ML, Buzzi A, Simonato M, Achsel T, Bagni C. Absence of RNA-binding protein FXR2P prevents prolonged phase of kainate-induced seizures. EMBO Rep 2021; 22:e51404. [PMID: 33779029 PMCID: PMC8024897 DOI: 10.15252/embr.202051404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 01/26/2021] [Accepted: 01/29/2021] [Indexed: 12/26/2022] Open
Abstract
Status epilepticus (SE) is a condition in which seizures are not self-terminating and thereby pose a serious threat to the patient's life. The molecular mechanisms underlying SE are likely heterogeneous and not well understood. Here, we reveal a role for the RNA-binding protein Fragile X-Related Protein 2 (FXR2P) in SE. Fxr2 KO mice display reduced sensitivity specifically to kainic acid-induced SE. Immunoprecipitation of FXR2P coupled to next-generation sequencing of associated mRNAs shows that FXR2P targets are enriched in genes that encode glutamatergic post-synaptic components. Of note, the FXR2P target transcriptome has a significant overlap with epilepsy and SE risk genes. In addition, Fxr2 KO mice fail to show sustained ERK1/2 phosphorylation induced by KA and present reduced burst activity in the hippocampus. Taken together, our findings show that the absence of FXR2P decreases the expression of glutamatergic proteins, and this decrease might prevent self-sustained seizures.
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Affiliation(s)
- Adrian C Lo
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Nicholas Rajan
- Department of Neurosciences and Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Denise Gastaldo
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Ludovic Telley
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Muna L Hilal
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Andrea Buzzi
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
| | - Michele Simonato
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy.,Division of Neuroscience, IRCCS San Raffaele Hospital, Milan, Italy
| | - Tilmann Achsel
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Claudia Bagni
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland.,Department of Neurosciences and Leuven Brain Institute, KU Leuven, Leuven, Belgium.,Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
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65
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Atli EI, Atli E, Yalcintepe S, Demir S, Kalkan R, Eker D, Gurkan H. Customized Targeted Massively Parallel Sequencing Enables More Precisely Diagnosis of Patients with Epilepsy. Intern Med J 2021; 52:1174-1184. [PMID: 33528079 DOI: 10.1111/imj.15219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/18/2021] [Accepted: 01/23/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND Advancement in genetic technology has led to the identification of an increasing number of genes in epilepsy. This will provide a huge information in clinical practice and improve diagnosis and treatment of epilepsy. METHODS this was a single-center retrospective cohort study of 80 patients who underwent NGS testing with customize epilepsy panel. RESULTS In total 54 out of 80 patients (67, 5%), pathogenic / likely pathogenic and variants of uncertain significance variants were identified according to ACMG criteria. Pathogenic or likely pathogenic variants (n=35) were identified in 29 out of 80 individuals (36.25%). Variants of uncertain significance (VOUS) (n=34) have identified in 28 out of 80 patients (35%). Pathogenic, likely pathogenic, and variants of uncertain significance (VOUS) were most frequently identified in TSC2 (n = 11), SCN1A (n = 6) and TSC1 (n = 5) genes. Other common genes were KCNQ2 (n = 3), AMT (n = 3), CACNA1H (n = 3), CLCN2 (n = 3), MECP2 (n = 2), ASAH1 (n = 2) and SLC2A1 (n = 2). CONCLUSIONS NGS based testing panels contributes the diagnosis of epilepsy and may change the clinical management by preventing unnecessary and potentially harmful diagnostic procedures and management in patients. Thus, our results highlighted the benefit of genetic testing in children suffered with epilepsy. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Emine Ikbal Atli
- Faculty of Medicine, Department of Medical Genetics, Edirne, Trakya University, Edirne, Turkey
| | - Engin Atli
- Faculty of Medicine, Department of Medical Genetics, Edirne, Trakya University, Edirne, Turkey
| | - Sinem Yalcintepe
- Faculty of Medicine, Department of Medical Genetics, Edirne, Trakya University, Edirne, Turkey
| | - Selma Demir
- Faculty of Medicine, Department of Medical Genetics, Edirne, Trakya University, Edirne, Turkey
| | - Rasime Kalkan
- Faculty of Medicine, Department of Medical Genetics, Near East University, Nicosia, Cyprus
| | - Damla Eker
- Faculty of Medicine, Department of Medical Genetics, Edirne, Trakya University, Edirne, Turkey
| | - Hakan Gurkan
- Faculty of Medicine, Department of Medical Genetics, Edirne, Trakya University, Edirne, Turkey
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Ye Z, Chatterton Z, Pflueger J, Damiano JA, McQuillan L, Simon Harvey A, Malone S, Do H, Maixner W, Schneider A, Nolan B, Wood M, Lee WS, Gillies G, Pope K, Wilson M, Lockhart PJ, Dobrovic A, Scheffer IE, Bahlo M, Leventer RJ, Lister R, Berkovic SF, Hildebrand MS. Cerebrospinal fluid liquid biopsy for detecting somatic mosaicism in brain. Brain Commun 2021; 3:fcaa235. [PMID: 33738444 PMCID: PMC7954394 DOI: 10.1093/braincomms/fcaa235] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 01/08/2023] Open
Abstract
Brain somatic mutations are an increasingly recognized cause of epilepsy, brain malformations and autism spectrum disorders and may be a hidden cause of other neurodevelopmental and neurodegenerative disorders. At present, brain mosaicism can be detected only in the rare situations of autopsy or brain biopsy. Liquid biopsy using cell-free DNA derived from cerebrospinal fluid has detected somatic mutations in malignant brain tumours. Here, we asked if cerebrospinal fluid liquid biopsy can be used to detect somatic mosaicism in non-malignant brain diseases. First, we reliably quantified cerebrospinal fluid cell-free DNA in 28 patients with focal epilepsy and 28 controls using droplet digital PCR. Then, in three patients we identified somatic mutations in cerebrospinal fluid: in one patient with subcortical band heterotopia the LIS1 p. Lys64* variant at 9.4% frequency; in a second patient with focal cortical dysplasia the TSC1 p. Phe581His*6 variant at 7.8% frequency; and in a third patient with ganglioglioma the BRAF p. Val600Glu variant at 3.2% frequency. To determine if cerebrospinal fluid cell-free DNA was brain-derived, whole-genome bisulphite sequencing was performed and brain-specific DNA methylation patterns were found to be significantly enriched (P = 0.03). Our proof of principle study shows that cerebrospinal fluid liquid biopsy is valuable in investigating mosaic neurological disorders where brain tissue is unavailable.
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Affiliation(s)
- Zimeng Ye
- Department of Medicine (Austin Health), University of Melbourne, Melbourne, Victoria 3084, Australia
| | - Zac Chatterton
- Brain and Mind Centre, Sydney Medical School, The University of Sydney, Sydney, New South Wales 2050, Australia
| | - Jahnvi Pflueger
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, Western Australia 6009, Australia
- Harry Perkins Institute of Medical Research, Perth, Western Australia 6150, Australia
| | - John A Damiano
- Department of Medicine (Austin Health), University of Melbourne, Melbourne, Victoria 3084, Australia
| | - Lara McQuillan
- Department of Medicine (Austin Health), University of Melbourne, Melbourne, Victoria 3084, Australia
| | - A Simon Harvey
- Murdoch Children’s Research Institute, Melbourne, Victoria 3052, Australia
- Department of Paediatrics, University of Melbourne, Royal Children’s Hospital, Melbourne, Victoria 3052, Australia
- Department of Neurology, Royal Children’s Hospital, Melbourne, Victoria 3052, Australia
| | - Stephen Malone
- Department of Neurosciences, Queensland Children’s Hospital, Brisbane, Queensland 4101, Australia
| | - Hongdo Do
- Department of Anatomical Pathology, St. Vincent’s Hospital, Melbourne, Victoria 3065, Australia
- School of Cancer Medicine, La Trobe University, Melbourne, Victoria 3086, Australia
- Department of Clinical Pathology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Wirginia Maixner
- Department of Neurosurgery, Royal Children’s Hospital, Melbourne, Victoria 3052, Australia
| | - Amy Schneider
- Department of Medicine (Austin Health), University of Melbourne, Melbourne, Victoria 3084, Australia
| | - Bernadette Nolan
- Department of Neurosciences, Queensland Children’s Hospital, Brisbane, Queensland 4101, Australia
| | - Martin Wood
- Neurosurgical Department, Queensland Children’s Hospital, Brisbane, Queensland 4101, Australia
| | - Wei Shern Lee
- Murdoch Children’s Research Institute, Melbourne, Victoria 3052, Australia
- Department of Paediatrics, University of Melbourne, Royal Children’s Hospital, Melbourne, Victoria 3052, Australia
| | - Greta Gillies
- Murdoch Children’s Research Institute, Melbourne, Victoria 3052, Australia
- Department of Paediatrics, University of Melbourne, Royal Children’s Hospital, Melbourne, Victoria 3052, Australia
| | - Kate Pope
- Murdoch Children’s Research Institute, Melbourne, Victoria 3052, Australia
| | - Michael Wilson
- Murdoch Children’s Research Institute, Melbourne, Victoria 3052, Australia
- Department of Paediatrics, University of Melbourne, Royal Children’s Hospital, Melbourne, Victoria 3052, Australia
| | - Paul J Lockhart
- Murdoch Children’s Research Institute, Melbourne, Victoria 3052, Australia
- Department of Paediatrics, University of Melbourne, Royal Children’s Hospital, Melbourne, Victoria 3052, Australia
| | - Alexander Dobrovic
- School of Cancer Medicine, La Trobe University, Melbourne, Victoria 3086, Australia
- Department of Clinical Pathology, University of Melbourne, Melbourne, Victoria 3010, Australia
- Translational Genomics and Epigenomics Laboratory, Olivia Newton-John Cancer Research Institute, Melbourne, Victoria 3084, Australia
| | - Ingrid E Scheffer
- Department of Medicine (Austin Health), University of Melbourne, Melbourne, Victoria 3084, Australia
- Murdoch Children’s Research Institute, Melbourne, Victoria 3052, Australia
- Department of Paediatrics, University of Melbourne, Royal Children’s Hospital, Melbourne, Victoria 3052, Australia
- Department of Neurology, Royal Children’s Hospital, Melbourne, Victoria 3052, Australia
| | - Melanie Bahlo
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Richard J Leventer
- Murdoch Children’s Research Institute, Melbourne, Victoria 3052, Australia
- Department of Paediatrics, University of Melbourne, Royal Children’s Hospital, Melbourne, Victoria 3052, Australia
- Department of Neurology, Royal Children’s Hospital, Melbourne, Victoria 3052, Australia
| | - Ryan Lister
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, Western Australia 6009, Australia
- Harry Perkins Institute of Medical Research, Perth, Western Australia 6150, Australia
| | - Samuel F Berkovic
- Department of Medicine (Austin Health), University of Melbourne, Melbourne, Victoria 3084, Australia
| | - Michael S Hildebrand
- Department of Medicine (Austin Health), University of Melbourne, Melbourne, Victoria 3084, Australia
- Murdoch Children’s Research Institute, Melbourne, Victoria 3052, Australia
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67
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Li Y, Tymchuk S, Barry J, Muppidi S, Le S. Antibody Prevalence in Epilepsy before Surgery (APES) in drug-resistant focal epilepsy. Epilepsia 2021; 62:720-728. [PMID: 33464599 DOI: 10.1111/epi.16820] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 12/26/2020] [Accepted: 12/27/2020] [Indexed: 12/17/2022]
Abstract
OBJECTIVE There is a growing recognition of immune-mediated causes in patients with focal drug-resistant epilepsy (DRE); however, they are not systematically assessed in the pre-surgical diagnostic workup. Early diagnosis and initiation of immunotherapy is associated with a favorable outcome in immune-mediated seizures. Patients with refractory focal epilepsy with neuronal antibodies (Abs) tend to have a worse surgical prognosis when compared to other etiologies. METHODS We studied the prevalence of serum Abs in patients ≥18 years of age with DRE of unknown cause before surgery. We proposed and calculated a clinical APES (Antibody Prevalence in Epilepsy before Surgery) score for each subject, which was modified based on Dubey's previously published APE2 score. RESULTS`: A total of 335 patients were screened and 86 subjects were included in final analysis. The mean age at the time of recruitment was 44.84 ± 14.86 years, with age at seizure onset 30.89 ± 19.88 years. There were no significant differences among baseline clinical features between retrospective and prospective sub-cohorts. The prevalence of at least one positive Ab was 33.72%, and central nervous system (CNS)-specific Abs was 8.14%. APES score ≥4 showed slightly better overall prediction (area under the curve [AUC]: 0.84 vs 0.74) and higher sensitivity (100% vs 71.4%), with slightly lower but similar specificity (44.3% vs 49.4%), when compared to APE2 score ≥4. For subjects who had available positron emission tomography (PET) results and all components of APES score (n = 60), the sensitivity of APES score ≥4 yielded a similar prediction potential with an AUC of 0.80. SIGNIFICANCE Our findings provide persuasive evidence that a subset of patients with focal DRE have potentially immune-mediated causes. We propose an APES score to help identify patients who may benefit from a workup for immune etiologies during the pre-surgical evaluation for focal refractory epilepsy with unknown cause.
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Affiliation(s)
- Yi Li
- Stanford Comprehensive Epilepsy Center, Stanford University, Palo Alto, CA, USA
| | - Sarah Tymchuk
- Department of Psychiatry, University of Alberta Hospital, Alberta, Canada
| | - John Barry
- Stanford Department of Psychiatry, Stanford University, Palo Alto, CA, USA
| | - Srikanth Muppidi
- Stanford Department of Neurology, Stanford University, Palo Alto, CA, USA
| | - Scheherazade Le
- Stanford Comprehensive Epilepsy Center, Stanford University, Palo Alto, CA, USA
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68
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Dare SS, Merlo E, Rodriguez Curt J, Ekanem PE, Hu N, Berni J. Drosophila para bss Flies as a Screening Model for Traditional Medicine: Anticonvulsant Effects of Annona senegalensis. Front Neurol 2021; 11:606919. [PMID: 33519685 PMCID: PMC7838503 DOI: 10.3389/fneur.2020.606919] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/09/2020] [Indexed: 01/02/2023] Open
Abstract
Epilepsy is among the most common serious neurological disorders and affects around 50 million people worldwide, 80% of which live in developing countries. Despite the introduction of several new Anti-Epileptic Drugs (AEDs) in the last two decades, one third of treated patients have seizures refractory to pharmacotherapy. This highlights the need to develop new treatments with drugs targeting alternative seizure-induction mechanisms. Traditional medicine (TM) is used for the treatment of epilepsy in many developing countries and could constitute an affordable and accessible alternative to AEDs, but a lack of pre-clinical and clinical testing has so far prevented its wider acceptance worldwide. In this study we used Drosophila melanogaster paralyticbangsensitive(parabss) mutants as a model for epileptic seizure screening and tested, for the first time, the anti-seizure effect of a non-commercial AED. We evaluated the effect of the African custard-apple, Annona senegalensis, which is commonly used as a TM for the treatment of epilepsy in rural Africa, and compared it with the classical AED phenytoin. Our results showed that a stem bark extract from A. senegalensis was significantly more effective than a leaf extract and similar to phenytoin in the prevention and control of seizure-like behavior. These results support that Drosophila constitutes a robust animal model for the screening of TM with potential value for the treatment of intractable epilepsy.
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Affiliation(s)
- Samuel S Dare
- School of Medicine, Kabale University, Kabale, Uganda.,Department of Anatomy, Kampala International University, Kampala, Uganda
| | - Emiliano Merlo
- Facultad de Medicina, Instituto de Fisiología y Biofísica (IFIBIO)-Houssay, Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,School of Psychology, University of Sussex, Brighton, United Kingdom
| | - Jesus Rodriguez Curt
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
| | - Peter E Ekanem
- Anatomy Unit, Institute of Biomedical Sciences, College of Health Sciences, Mekelle University, Mekelle, Ethiopia
| | - Nan Hu
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Jimena Berni
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
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69
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Alten B, Zhou Q, Shin OH, Esquivies L, Lin PY, White KI, Sun R, Chung WK, Monteggia LM, Brunger AT, Kavalali ET. Role of Aberrant Spontaneous Neurotransmission in SNAP25-Associated Encephalopathies. Neuron 2020; 109:59-72.e5. [PMID: 33147442 DOI: 10.1016/j.neuron.2020.10.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 09/09/2020] [Accepted: 10/07/2020] [Indexed: 01/19/2023]
Abstract
SNARE (soluble N-ethylmaleimide sensitive factor attachment protein receptor) complex, composed of synaptobrevin, syntaxin, and SNAP25, forms the essential fusion machinery for neurotransmitter release. Recent studies have reported several mutations in the gene encoding SNAP25 as a causative factor for developmental and epileptic encephalopathies of infancy and childhood with diverse clinical manifestations. However, it remains unclear how SNAP25 mutations give rise to these disorders. Here, we show that although structurally clustered mutations in SNAP25 give rise to related synaptic transmission phenotypes, specific alterations in spontaneous neurotransmitter release are a key factor to account for disease heterogeneity. Importantly, we identified a single mutation that augments spontaneous release without altering evoked release, suggesting that aberrant spontaneous release is sufficient to cause disease in humans.
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Affiliation(s)
- Baris Alten
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37240-7933, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA
| | - Qiangjun Zhou
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37240-7933, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37240-7933, USA
| | - Ok-Ho Shin
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37240-7933, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA
| | - Luis Esquivies
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Pei-Yi Lin
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37240-7933, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA
| | - K Ian White
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Rong Sun
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37240-7933, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37240-7933, USA
| | - Wendy K Chung
- Department of Pediatrics (in Medicine), Columbia University Medical Center, New York, NY 10032, USA
| | - Lisa M Monteggia
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37240-7933, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA
| | - Axel T Brunger
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Ege T Kavalali
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37240-7933, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA.
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70
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Gamirova RG, Gamirova RR, Esin RG. [Genetics of epilepsy: successes, problems and development prospects]. Zh Nevrol Psikhiatr Im S S Korsakova 2020; 120:144-150. [PMID: 33081460 DOI: 10.17116/jnevro2020120091144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The authors present a detailed review of current advances in the field of genetics of epilepsy. Separately, new views on the etiology and pathogenesis of genetic epileptic encephalopathies, focal epilepsy and idiopathic generalized epilepsies are examined. The authors emphasize the importance of genetic discoveries for the clinical practice, including the prospects in the development of patients' personalized treatment. A comparative analysis of the value of various methods of genetic research in the diagnosis of epilepsy, methods of integrating molecular genetic analyses into everyday practical medicine is presented.
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Affiliation(s)
- R G Gamirova
- Kazan State Medical Academy - branch of Russian Medical Academy of Continuing Professional Education, Kazan, Russia.,Kazan (Volga Region) Federal University, Kazan, Russia
| | - R R Gamirova
- Kazan (Volga Region) Federal University, Kazan, Russia
| | - R G Esin
- Kazan State Medical Academy - branch of Russian Medical Academy of Continuing Professional Education, Kazan, Russia.,Kazan (Volga Region) Federal University, Kazan, Russia
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71
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Chen Z, Rollo B, Antonic-Baker A, Anderson A, Ma Y, O'Brien TJ, Ge Z, Wang X, Kwan P. New era of personalised epilepsy management. BMJ 2020; 371:m3658. [PMID: 33037001 PMCID: PMC7541035 DOI: 10.1136/bmj.m3658] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The trial and error approach to epilepsy treatment has not changed for over a century but machine learning and patient derived stem cells promise a personalised and more effective strategy, argue Patrick Kwan and colleagues
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Affiliation(s)
- Zhibin Chen
- Chongqing Key Laboratory of Neurology, First Affiliated Hospital, Chongqing Medical University, Chongqing, China
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia
| | - Ben Rollo
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
| | - Ana Antonic-Baker
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
| | - Alison Anderson
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
| | - Yuanlin Ma
- Chongqing Key Laboratory of Neurology, First Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
- Department of Neurology, Alfred Hospital, Melbourne, Australia
| | - Zongyuan Ge
- Faculty of Engineering, Monash University, Melbourne, Australia
- eResearch Centre, Monash University, Melbourne, Australia
- Airdoc Research Australia, Melbourne, Australia
| | - Xuefeng Wang
- Chongqing Key Laboratory of Neurology, First Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Patrick Kwan
- Chongqing Key Laboratory of Neurology, First Affiliated Hospital, Chongqing Medical University, Chongqing, China
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia
- Department of Neurology, Alfred Hospital, Melbourne, Australia
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72
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Stödberg T, Tomson T, Barbaro M, Stranneheim H, Anderlid BM, Carlsson S, Åmark P, Wedell A. Epilepsy syndromes, etiologies, and the use of next-generation sequencing in epilepsy presenting in the first 2 years of life: A population-based study. Epilepsia 2020; 61:2486-2499. [PMID: 32964447 PMCID: PMC7756847 DOI: 10.1111/epi.16701] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/28/2020] [Accepted: 08/31/2020] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Population-based data on epilepsy syndromes and etiologies in early onset epilepsy are scarce. The use of next-generation sequencing (NGS) has hitherto not been reported in this context. The aim of this study is to describe children with epilepsy onset before 2 years of age, and to explore to what degree whole exome and whole genome sequencing (WES/WGS) can help reveal a molecular genetic diagnosis. METHODS Children presenting with a first unprovoked epileptic seizure before age 2 years and registered in the Stockholm Incidence Registry of Epilepsy (SIRE) between September 1, 2001 and December 31, 2006, were retrieved and their medical records up to age 7 years reviewed. Children who met the epilepsy criteria were included in the study cohort. WES/WGS was offered in cases of suspected genetic etiology regardless of whether a structural or metabolic diagnosis had been established. RESULTS One hundred sixteen children were included, of which 88 had seizure onset during the first year of life and 28 during the second, corresponding to incidences of 139 and 42/100 000 person-years, respectively. An epilepsy syndrome could be diagnosed in 54% of cases, corresponding to a birth prevalence of 1/1100. Structural etiology was revealed in 34% of cases, a genetic cause in 20%, and altogether etiology was known in 65% of children. The highest diagnostic yield was seen in magnetic resonance imaging (MRI) with 65% revealing an etiology. WES/WGS was performed in 26/116 cases (22%), with a diagnostic yield of 58%. SIGNIFICANCE Epilepsy syndromes can be diagnosed and etiologies revealed in a majority of early onset cases. NGS can identify a molecular diagnosis in a substantial number of children, and should be included in the work-up, especially in cases of epileptic encephalopathy, cerebral malformation, or metabolic disease without molecular diagnosis. A genetic diagnosis is essential to genetic counselling, prenatal diagnostics, and precision therapy.
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Affiliation(s)
- Tommy Stödberg
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.,Department of Pediatric Neurology, Karolinska University Hospital, Stockholm, Sweden
| | - Torbjörn Tomson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Michela Barbaro
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Henrik Stranneheim
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden.,Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Britt-Marie Anderlid
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Sofia Carlsson
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Per Åmark
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Anna Wedell
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden.,Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
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73
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Hori K, Tsujikawa S, Novakovic MM, Yamashita M, Prakriya M. Regulation of chemoconvulsant-induced seizures by store-operated Orai1 channels. J Physiol 2020; 598:5391-5409. [PMID: 32851638 DOI: 10.1113/jp280119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/25/2020] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS Temporal lobe epilepsy is a complex neurological disease caused by imbalance of excitation and inhibition in the brain. Growing literature implicates altered Ca2+ signalling in many aspects of epilepsy but the diversity of Ca2+ channels that regulate this syndrome are not well-understood. Here, we report that mice lacking the store-operated Ca2+ channel, Orai1, in the brain show markedly stronger seizures in response to the chemoconvulsants, kainic acid and pilocarpine. Electrophysiological analysis reveals that selective deletion of Orai1 channels in inhibitory neurons disables chemoconvulsant-induced excitation of GABAergic neurons in the CA1 hippocampus. Likewise, deletion of Orai1 in GABAergic neurons abrogates the chemoconvulsant-induced burst of spontaneous inhibitory postsynaptic currents (sIPSCs) on CA1 pyramidal neurons in the hippocampus. This loss of chemoconvulsant inhibition likely aggravates status epilepticus in Orai1 KO mice. These results identify Orai1 channels as regulators of hippocampal interneuron excitability and seizures. ABSTRACT Store-operated Orai1 channels are a major mechanism for Ca2+ entry in many cells and mediate numerous functions including gene expression, cytokine production and gliotransmitter release. Orai1 is expressed in many regions of the mammalian brain; however, its role in regulating neuronal excitability, synaptic function and brain disorders has only now begun to be investigated. To investigate a potential role of Orai1 channels in status epilepticus induced by chemoconvulsants, we examined acute seizures evoked by intraperitoneal injections of kainic acid (KA) and pilocarpine in mice with a conditional deletion of Orai1 (or its activator STIM1) in the brain. Brain-specific Orai1 and STIM1 knockout (KO) mice exhibited significantly stronger seizures (P = 0.00003 and P < 0.00001), and higher chemoconvulsant-induced mortality (P = 0.02) compared with wildtype (WT) littermates. Electrophysiological recordings in hippocampal brain slices revealed that KA stimulated the activity of inhibitory interneurons in the CA1 hippocampus (P = 0.04) which failed to occur in Orai1 KO mice. Further, KA and pilocarpine increased the frequency of spontaneous IPSCs in CA1 pyramidal neurons >twofold (KA: P = 0.04; pilocarpine: P = 0.0002) which was abolished in Orai1 KO mice. Mice with selective deletion of Orai1 in GABAergic neurons alone also showed stronger seizures to KA (P = 0.001) and pilocarpine (P < 0.00001) and loss of chemoconvulsant-induced increases in sIPSC responses compared with WT controls. We conclude that Orai1 channels regulate chemoconvulsant-induced excitation in GABAergic neurons and that destabilization of the excitatory/inhibitory balance in Orai1 KO mice aggravates chemoconvulsant-mediated seizures. These results identify Orai1 channels as novel molecular regulators of hippocampal neuronal excitability and seizures.
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Affiliation(s)
- Kotaro Hori
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Shogo Tsujikawa
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Michaela M Novakovic
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Megumi Yamashita
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Murali Prakriya
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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74
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Menezes LFS, Sabiá Júnior EF, Tibery DV, Carneiro LDA, Schwartz EF. Epilepsy-Related Voltage-Gated Sodium Channelopathies: A Review. Front Pharmacol 2020; 11:1276. [PMID: 33013363 PMCID: PMC7461817 DOI: 10.3389/fphar.2020.01276] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/31/2020] [Indexed: 12/29/2022] Open
Abstract
Epilepsy is a disease characterized by abnormal brain activity and a predisposition to generate epileptic seizures, leading to neurobiological, cognitive, psychological, social, and economic impacts for the patient. There are several known causes for epilepsy; one of them is the malfunction of ion channels, resulting from mutations. Voltage-gated sodium channels (NaV) play an essential role in the generation and propagation of action potential, and malfunction caused by mutations can induce irregular neuronal activity. That said, several genetic variations in NaV channels have been described and associated with epilepsy. These mutations can affect channel kinetics, modifying channel activation, inactivation, recovery from inactivation, and/or the current window. Among the NaV subtypes related to epilepsy, NaV1.1 is doubtless the most relevant, with more than 1500 mutations described. Truncation and missense mutations are the most observed alterations. In addition, several studies have already related mutated NaV channels with the electrophysiological functioning of the channel, aiming to correlate with the epilepsy phenotype. The present review provides an overview of studies on epilepsy-associated mutated human NaV1.1, NaV1.2, NaV1.3, NaV1.6, and NaV1.7.
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Affiliation(s)
- Luis Felipe Santos Menezes
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Elias Ferreira Sabiá Júnior
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Diogo Vieira Tibery
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Lilian Dos Anjos Carneiro
- Faculdade de Medicina, Centro Universitário Euro Americano, Brasília, Brazil.,Faculdade de Medicina, Centro Universitário do Planalto Central, Brasília, Brazil
| | - Elisabeth Ferroni Schwartz
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
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Abstract
BACKGROUND Retrospective observational study to determine diagnostic yield and utility of genetic testing in children with epilepsy attending the Epilepsy Clinic at Children's Hospital, London, Ontario, Canada. METHODS Children (birth-18 years) with epilepsy, who were seen in a 10-year period (January 1, 2008-March 31, 2018), were selected using defined inclusion criteria and by combining clinic datasets and laboratory records. RESULTS In total, 105 children (52.38% male and 47.61% female) with a variety of seizures were included in the analysis. Developmental delay was documented in the majority (83; 79.04%). Overall, a genetic diagnosis was established in 24 (22.85%) children. The diagnostic yield was highest for whole-exome sequencing (WES), at 35.71%. The yield from microarray was 8.33%. Yields of single-gene testing (18.60%) and targeted multigene panel testing (19.23%) were very similar. Several likely pathogenic and pathogenic variants not previously reported were identified and categorized using ACMG criteria. All diagnosed patients underwent a review of anti-seizure medication management and received counseling on natural history of their disease, possible complications, recurrence risks, and possibilities of preimplantation or prenatal genetic diagnosis. CONCLUSIONS Our study confirms the multiple benefits of detecting a genetic etiology in children with epilepsy. Similar yields in single versus multigene testing underscore the importance of accurate clinical phenotyping. Patients with epilepsy and their caregivers in Ontario would undoubtedly benefit from repatriation of multigene panels and WES to the province.
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76
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Božina N, Sporiš IŠ, Božina T, Klarica-Domjanović I, Tvrdeić A, Sporiš D. Pharmacogenetics and the treatment of epilepsy: what do we know? Pharmacogenomics 2020; 20:1093-1101. [PMID: 31588875 DOI: 10.2217/pgs-2019-0085] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Seizure control with antiepileptic drugs (AEDs) as well as susceptibility to adverse drug reactions varies among individuals with epilepsy. This interindividual variability is partly determined by genetic factors. However, genetic testing to predict the efficacy and toxicity of AEDs is limited and genetic variability is, as yet, largely unexplainable. Accordingly, genetic testing can only be advised in a very limited number of cases in clinical routine. Currently, by applying different methodologies, many trials have been undertaken to evaluate cost benefits of preventive pharmacogenetic analysis for patients. There is significant progress in sequencing technologies, and focus is on next-generation sequencing-based methods, like exome and genome sequencing. In this review, an overview of the current scientific knowledge considering the pharmacogenetics of AEDs is given.
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Affiliation(s)
- Nada Božina
- Department of Laboratory Diagnostics, Division of Pharmacogenomics & Therapy Individualiation, University Hospital Centre Zagreb, 10000 Zagreb, Croatia.,Department of Pharmacology, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Ivana Šušak Sporiš
- Department of Neurology, University Hospital Dubrava, 10000 Zagreb, Croatia.,Faculty of Dental Medicine & Health Osijek, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia
| | - Tamara Božina
- Department of Medical Chemistry, Biochemistry & Clinical Chemistry, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | | | - Ante Tvrdeić
- Department of Pharmacology, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Davor Sporiš
- Department of Neurology, University Hospital Dubrava, 10000 Zagreb, Croatia.,Faculty of Dental Medicine & Health Osijek, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia
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77
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The role of targeted gene panel in pediatric drug-resistant epilepsy. Epilepsy Behav 2020; 106:107003. [PMID: 32169601 DOI: 10.1016/j.yebeh.2020.107003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/21/2020] [Accepted: 02/23/2020] [Indexed: 11/23/2022]
Abstract
About 10-30% of pediatric patients with epilepsy have drug-resistant epilepsy. Genetic panels may be useful in identifying etiology and guiding treatment in pediatric patients with drug-resistant epilepsy. In our tertiary center, we used two epilepsy panels, an initial 24-genes panel followed by a more comprehensive 122-genes panel to screen for genetic cause over recent 2 years. A total of 96 patients with drug-resistant epilepsy were evaluated using the 24-genes panel, which revealed 10 (10.4%) of the patients with pathogenic variants. Another 22 patients without causative genetic variants using first-gene panel were evaluated using the 122-genes panel. Out of the 22 patients, 4 had pathogenic variants, and 6 had variants of unknown significance. The total yield rate for the second panel was 18.2% (4/22). In conclusion, although whole exome sequencing has entered clinical practice, epilepsy gene panels may still play some roles because of lower cost and faster time, especially in those with fever-associated epilepsy.
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78
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Abstract
Epilepsy encompasses a group of heterogeneous brain diseases that affect more than 50 million people worldwide. Epilepsy may have discernible structural, infectious, metabolic, and immune etiologies; however, in most people with epilepsy, no obvious cause is identifiable. Based initially on family studies and later on advances in gene sequencing technologies and computational approaches, as well as the establishment of large collaborative initiatives, we now know that genetics plays a much greater role in epilepsy than was previously appreciated. Here, we review the progress in the field of epilepsy genetics and highlight molecular discoveries in the most important epilepsy groups, including those that have been long considered to have a nongenetic cause. We discuss where the field of epilepsy genetics is moving as it enters a new era in which the genetic architecture of common epilepsies is starting to be unraveled.
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Affiliation(s)
- Piero Perucca
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria 3000, Australia.,Departments of Medicine and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Melbourne, Victoria 3050, Australia.,Department of Neurology, Alfred Health, Melbourne, Victoria 3000, Australia
| | - Melanie Bahlo
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Victoria 3084, Australia;
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Moreau C, Rébillard RM, Wolking S, Michaud J, Tremblay F, Girard A, Bouchard J, Minassian B, Laprise C, Cossette P, Girard SL. Polygenic risk scores of several subtypes of epilepsies in a founder population. NEUROLOGY-GENETICS 2020; 6:e416. [PMID: 32337343 PMCID: PMC7164970 DOI: 10.1212/nxg.0000000000000416] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/13/2020] [Indexed: 02/04/2023]
Abstract
Objective Polygenic risk scores (PRSs) are used to quantify the cumulative effects of a number of genetic variants, which may individually have a very small effect on susceptibility to a disease; we used PRSs to better understand the genetic contribution to common epilepsy and its subtypes. Methods We first replicated previous single associations using 373 unrelated patients. We then calculated PRSs in the same French Canadian patients with epilepsy divided into 7 epilepsy subtypes and population-based controls. We fitted a logistic mixed model to calculate the variance explained by the PRS using pseudo-R2 statistics. Results We show that the PRS explains more of the variance in idiopathic generalized epilepsy than in patients with nonacquired focal epilepsy. We also demonstrate that the variance explained is different within each epilepsy subtype. Conclusions Globally, we support the notion that PRSs provide a reliable measure to rightfully estimate the contribution of genetic factors to the pathophysiologic mechanism of epilepsies, but further studies are needed on PRSs before they can be used clinically.
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Affiliation(s)
- Claudia Moreau
- Centre Intersectoriel en Santé Durable (C.M., F.T., A.G., J.B., C.L., S.L.G.), Université du Québec à Chicoutimi, Saguenay; Axe Neurosciences (R.-M.R., S.W., P.C.), Centre de recherche de l'Université de Montréal, Université de Montréal; Centre de recherche du CHU Ste-Justine (J.M.), Université de Montréal, Canada; and Department of Pediatrics and Neurology and Neurotherapeutics (B.M.), UT Southwestern Medical Center, TX
| | - Rose-Marie Rébillard
- Centre Intersectoriel en Santé Durable (C.M., F.T., A.G., J.B., C.L., S.L.G.), Université du Québec à Chicoutimi, Saguenay; Axe Neurosciences (R.-M.R., S.W., P.C.), Centre de recherche de l'Université de Montréal, Université de Montréal; Centre de recherche du CHU Ste-Justine (J.M.), Université de Montréal, Canada; and Department of Pediatrics and Neurology and Neurotherapeutics (B.M.), UT Southwestern Medical Center, TX
| | - Stefan Wolking
- Centre Intersectoriel en Santé Durable (C.M., F.T., A.G., J.B., C.L., S.L.G.), Université du Québec à Chicoutimi, Saguenay; Axe Neurosciences (R.-M.R., S.W., P.C.), Centre de recherche de l'Université de Montréal, Université de Montréal; Centre de recherche du CHU Ste-Justine (J.M.), Université de Montréal, Canada; and Department of Pediatrics and Neurology and Neurotherapeutics (B.M.), UT Southwestern Medical Center, TX
| | - Jacques Michaud
- Centre Intersectoriel en Santé Durable (C.M., F.T., A.G., J.B., C.L., S.L.G.), Université du Québec à Chicoutimi, Saguenay; Axe Neurosciences (R.-M.R., S.W., P.C.), Centre de recherche de l'Université de Montréal, Université de Montréal; Centre de recherche du CHU Ste-Justine (J.M.), Université de Montréal, Canada; and Department of Pediatrics and Neurology and Neurotherapeutics (B.M.), UT Southwestern Medical Center, TX
| | - Frédérique Tremblay
- Centre Intersectoriel en Santé Durable (C.M., F.T., A.G., J.B., C.L., S.L.G.), Université du Québec à Chicoutimi, Saguenay; Axe Neurosciences (R.-M.R., S.W., P.C.), Centre de recherche de l'Université de Montréal, Université de Montréal; Centre de recherche du CHU Ste-Justine (J.M.), Université de Montréal, Canada; and Department of Pediatrics and Neurology and Neurotherapeutics (B.M.), UT Southwestern Medical Center, TX
| | - Alexandre Girard
- Centre Intersectoriel en Santé Durable (C.M., F.T., A.G., J.B., C.L., S.L.G.), Université du Québec à Chicoutimi, Saguenay; Axe Neurosciences (R.-M.R., S.W., P.C.), Centre de recherche de l'Université de Montréal, Université de Montréal; Centre de recherche du CHU Ste-Justine (J.M.), Université de Montréal, Canada; and Department of Pediatrics and Neurology and Neurotherapeutics (B.M.), UT Southwestern Medical Center, TX
| | - Joanie Bouchard
- Centre Intersectoriel en Santé Durable (C.M., F.T., A.G., J.B., C.L., S.L.G.), Université du Québec à Chicoutimi, Saguenay; Axe Neurosciences (R.-M.R., S.W., P.C.), Centre de recherche de l'Université de Montréal, Université de Montréal; Centre de recherche du CHU Ste-Justine (J.M.), Université de Montréal, Canada; and Department of Pediatrics and Neurology and Neurotherapeutics (B.M.), UT Southwestern Medical Center, TX
| | - Berge Minassian
- Centre Intersectoriel en Santé Durable (C.M., F.T., A.G., J.B., C.L., S.L.G.), Université du Québec à Chicoutimi, Saguenay; Axe Neurosciences (R.-M.R., S.W., P.C.), Centre de recherche de l'Université de Montréal, Université de Montréal; Centre de recherche du CHU Ste-Justine (J.M.), Université de Montréal, Canada; and Department of Pediatrics and Neurology and Neurotherapeutics (B.M.), UT Southwestern Medical Center, TX
| | - Catherine Laprise
- Centre Intersectoriel en Santé Durable (C.M., F.T., A.G., J.B., C.L., S.L.G.), Université du Québec à Chicoutimi, Saguenay; Axe Neurosciences (R.-M.R., S.W., P.C.), Centre de recherche de l'Université de Montréal, Université de Montréal; Centre de recherche du CHU Ste-Justine (J.M.), Université de Montréal, Canada; and Department of Pediatrics and Neurology and Neurotherapeutics (B.M.), UT Southwestern Medical Center, TX
| | - Patrick Cossette
- Centre Intersectoriel en Santé Durable (C.M., F.T., A.G., J.B., C.L., S.L.G.), Université du Québec à Chicoutimi, Saguenay; Axe Neurosciences (R.-M.R., S.W., P.C.), Centre de recherche de l'Université de Montréal, Université de Montréal; Centre de recherche du CHU Ste-Justine (J.M.), Université de Montréal, Canada; and Department of Pediatrics and Neurology and Neurotherapeutics (B.M.), UT Southwestern Medical Center, TX
| | - Simon L Girard
- Centre Intersectoriel en Santé Durable (C.M., F.T., A.G., J.B., C.L., S.L.G.), Université du Québec à Chicoutimi, Saguenay; Axe Neurosciences (R.-M.R., S.W., P.C.), Centre de recherche de l'Université de Montréal, Université de Montréal; Centre de recherche du CHU Ste-Justine (J.M.), Université de Montréal, Canada; and Department of Pediatrics and Neurology and Neurotherapeutics (B.M.), UT Southwestern Medical Center, TX
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Dadali EL, Mishina IA, Borovikov AO, Sharkov AA, Kanivets IV. [Clinical and genetic characteristics of epilepsy caused by mutations in the PCDH19 gene (OMIM: 300088)]. Zh Nevrol Psikhiatr Im S S Korsakova 2020; 120:55-61. [PMID: 32105270 DOI: 10.17116/jnevro202012001155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
AIM To analyze clinical and genetic characteristics of PCDH19-associated epilepsy in a sample of patients from the Russian population. MATERIAL AND METHODS The sample of patients with early epileptic encephalopathies included 16 people aged 10 month to 30 years. All patients underwent neurological examination according to standard methods, exome sequencing and EEG monitoring. RESULTS Most of the identified mutations led to a shift in the reading frame or the formation of a termination codon. Six of them were duplications, four were deletions of one nucleotide, and three were nonsense mutations. Consistent with earlier studies, the authors identified the polymorphism of clinical manifestations of seizures that did not depend on the type of mutation and its localization. CONCLUSION Based on the study of the clinical and genetic characteristics of the patients, the authors conclude that the so-called 'hot spots' are present in the PCDH19 gene, which are more common in the group of patients with mutations in this gene, and that the clinical picture of early infantile epileptic encephalopathy type 9 is variable.
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Affiliation(s)
- E L Dadali
- Federal State Budgetary Institution 'Research Centre for Medical Genetics', Moscow, Russia; Pirogov Russian National Research Medical University, Moscow, Russia
| | - I A Mishina
- Federal State Budgetary Institution 'Research Centre for Medical Genetics', Moscow, Russia
| | - A O Borovikov
- Federal State Budgetary Institution 'Research Centre for Medical Genetics', Moscow, Russia
| | - A A Sharkov
- Pirogov Russian National Research Medical University, Moscow, Russia
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81
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Lack of Association of Generic Brittle Status with Genetics and Physiologic Measures in Patients with Epilepsy. Pharm Res 2020; 37:60. [PMID: 32103380 DOI: 10.1007/s11095-020-2781-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 02/07/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE A patient was denoted to be generic brittle (GB) if they had a negative opinion about generics (e.g. prior history of a switch problem) or took the innovator brand of their most problematic anti-epileptic drug (AED) when generic was available. The aim of this hypothesis-generating study was to assess possible genetic and physiologic differences between GB and not GB patients with epilepsy. METHODS Patients (n = 148) with epilepsy were previously characterized as being either GB or not GB. Blood was collected from each subject for genotyping and physiologic testing. Genotyping for 24 single nucleotide polymorphisms (SNPs) and two copy number variants (CNVs) was performed across 12 genes in each patient. Forty-four physiologic tests were conducted in each patient. Chi square analysis was performed to assess for associations between genotyping results and GB status, as well as between physiologic test results and GB status. RESULTS No SNP or CNV discriminated GB status in genetic analysis (genotype or allele frequency). Physiologic test results in this study were not associated with GB status. CONCLUSIONS Questions from neurologists and patients about generics is frequently based on applicability of generic drug standards to individual subjects. However, findings here in patients with epilepsy did not uncover genetic or physiologic reasons that explained which patients were GB and which were not GB.
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Krenn M, Wagner M, Hotzy C, Graf E, Weber S, Brunet T, Lorenz-Depiereux B, Kasprian G, Aull-Watschinger S, Pataraia E, Stogmann E, Zimprich A, Strom TM, Meitinger T, Zimprich F. Diagnostic exome sequencing in non-acquired focal epilepsies highlights a major role of GATOR1 complex genes. J Med Genet 2020; 57:624-633. [PMID: 32086284 DOI: 10.1136/jmedgenet-2019-106658] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/17/2020] [Accepted: 01/22/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND The genetic architecture of non-acquired focal epilepsies (NAFEs) becomes increasingly unravelled using genome-wide sequencing datasets. However, it remains to be determined how this emerging knowledge can be translated into a diagnostic setting. To bridge this gap, we assessed the diagnostic outcomes of exome sequencing (ES) in NAFE. METHODS 112 deeply phenotyped patients with NAFE were included in the study. Diagnostic ES was performed, followed by a screen to detect variants of uncertain significance (VUSs) in 15 well-established focal epilepsy genes. Explorative gene prioritisation was used to identify possible novel candidate aetiologies with so far limited evidence for NAFE. RESULTS ES identified pathogenic or likely pathogenic (ie, diagnostic) variants in 13/112 patients (12%) in the genes DEPDC5, NPRL3, GABRG2, SCN1A, PCDH19 and STX1B. Two pathogenic variants were microdeletions involving NPRL3 and PCDH19. Nine of the 13 diagnostic variants (69%) were found in genes of the GATOR1 complex, a potentially druggable target involved in the mammalian target of rapamycin (mTOR) signalling pathway. In addition, 17 VUSs in focal epilepsy genes and 6 rare variants in candidate genes (MTOR, KCNA2, RBFOX1 and SCN3A) were detected. Five patients with reported variants had double hits in different genes, suggesting a possible (oligogenic) role of multiple rare variants. CONCLUSION This study underscores the molecular heterogeneity of NAFE with GATOR1 complex genes representing the by far most relevant genetic aetiology known to date. Although the diagnostic yield is lower compared with severe early-onset epilepsies, the high rate of VUSs and candidate variants suggests a further increase in future years.
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Affiliation(s)
- Martin Krenn
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Matias Wagner
- Institute of Human Genetics, Technical University Munich, Munich, Bayern, Germany.,Institute of Neurogenomics, Helmholtz Center Munich, Neuherberg, Bayern, Germany
| | - Christoph Hotzy
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Elisabeth Graf
- Institute of Human Genetics, Helmholtz Center Munich, Neuherberg, Bayern, Germany
| | - Sandrina Weber
- Institute of Human Genetics, Helmholtz Center Munich, Neuherberg, Bayern, Germany
| | - Theresa Brunet
- Institute of Human Genetics, Technical University Munich, Munich, Bayern, Germany
| | | | - Gregor Kasprian
- Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | | | | | | | | | - Tim M Strom
- Institute of Human Genetics, Technical University Munich, Munich, Bayern, Germany.,Institute of Human Genetics, Helmholtz Center Munich, Neuherberg, Bayern, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Technical University Munich, Munich, Bayern, Germany.,Institute of Human Genetics, Helmholtz Center Munich, Neuherberg, Bayern, Germany
| | - Fritz Zimprich
- Department of Neurology, Medical University of Vienna, Vienna, Austria
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83
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Semple BD, Dill LK, O'Brien TJ. Immune Challenges and Seizures: How Do Early Life Insults Influence Epileptogenesis? Front Pharmacol 2020; 11:2. [PMID: 32116690 PMCID: PMC7010861 DOI: 10.3389/fphar.2020.00002] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 01/03/2020] [Indexed: 12/16/2022] Open
Abstract
The development of epilepsy, a process known as epileptogenesis, often occurs later in life following a prenatal or early postnatal insult such as cerebral ischemia, stroke, brain trauma, or infection. These insults share common pathophysiological pathways involving innate immune activation including neuroinflammation, which is proposed to play a critical role in epileptogenesis. This review provides a comprehensive overview of the latest preclinical evidence demonstrating that early life immune challenges influence neuronal hyperexcitability and predispose an individual to later life epilepsy. Here, we consider the range of brain insults that may promote the onset of chronic recurrent spontaneous seizures at adulthood, spanning intrauterine insults (e.g. maternal immune activation), perinatal injuries (e.g. hypoxic–ischemic injury, perinatal stroke), and insults sustained during early postnatal life—such as fever-induced febrile seizures, traumatic brain injuries, infections, and environmental stressors. Importantly, all of these insults represent, to some extent, an immune challenge, triggering innate immune activation and implicating both central and systemic inflammation as drivers of epileptogenesis. Increasing evidence suggests that pro-inflammatory cytokines such as interleukin-1 and subsequent signaling pathways are important mediators of seizure onset and recurrence, as well as neuronal network plasticity changes in this context. Our current understanding of how early life immune challenges prime microglia and astrocytes will be explored, as well as how developmental age is a critical determinant of seizure susceptibility. Finally, we will consider the paradoxical phenomenon of preconditioning, whereby these same insults may conversely provide neuroprotection. Together, an improved appreciation of the neuroinflammatory mechanisms underlying the long-term epilepsy risk following early life insults may provide insight into opportunities to develop novel immunological anti-epileptogenic therapeutic strategies.
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Affiliation(s)
- Bridgette D Semple
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia.,Department of Neurology, Alfred Health, Melbourne, VIC, Australia
| | - Larissa K Dill
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Neurology, Alfred Health, Melbourne, VIC, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia.,Department of Neurology, Alfred Health, Melbourne, VIC, Australia
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84
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Burrows DRW, Samarut É, Liu J, Baraban SC, Richardson MP, Meyer MP, Rosch RE. Imaging epilepsy in larval zebrafish. Eur J Paediatr Neurol 2020; 24:70-80. [PMID: 31982307 PMCID: PMC7035958 DOI: 10.1016/j.ejpn.2020.01.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 01/03/2020] [Accepted: 01/04/2020] [Indexed: 12/19/2022]
Abstract
Our understanding of the genetic aetiology of paediatric epilepsies has grown substantially over the last decade. However, in order to translate improved diagnostics to personalised treatments, there is an urgent need to link molecular pathophysiology in epilepsy to whole-brain dynamics in seizures. Zebrafish have emerged as a promising new animal model for epileptic seizure disorders, with particular relevance for genetic and developmental epilepsies. As a novel model organism for epilepsy research they combine key advantages: the small size of larval zebrafish allows high throughput in vivo experiments; the availability of advanced genetic tools allows targeted modification to model specific human genetic disorders (including genetic epilepsies) in a vertebrate system; and optical access to the entire central nervous system has provided the basis for advanced microscopy technologies to image structure and function in the intact larval zebrafish brain. There is a growing body of literature describing and characterising features of epileptic seizures and epilepsy in larval zebrafish. Recently genetically encoded calcium indicators have been used to investigate the neurobiological basis of these seizures with light microscopy. This approach offers a unique window into the multiscale dynamics of epileptic seizures, capturing both whole-brain dynamics and single-cell behaviour concurrently. At the same time, linking observations made using calcium imaging in the larval zebrafish brain back to an understanding of epileptic seizures largely derived from cortical electrophysiological recordings in human patients and mammalian animal models is non-trivial. In this review we briefly illustrate the state of the art of epilepsy research in zebrafish with particular focus on calcium imaging of epileptic seizures in the larval zebrafish. We illustrate the utility of a dynamic systems perspective on the epileptic brain for providing a principled approach to linking observations across species and identifying those features of brain dynamics that are most relevant to epilepsy. In the following section we survey the literature for imaging features associated with epilepsy and epileptic seizures and link these to observations made from humans and other more traditional animal models. We conclude by identifying the key challenges still facing epilepsy research in the larval zebrafish and indicate strategies for future research to address these and integrate more directly with the themes and questions that emerge from investigating epilepsy in other model systems and human patients.
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Affiliation(s)
- D R W Burrows
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - É Samarut
- Department of Neurosciences, Research Center of the University of Montreal Hospital Center, Montreal, Quebec, Canada
| | - J Liu
- Department of Neurological Surgery and Weill Institute for Neuroscience, University of California, San Francisco, San Francisco, CA, USA
| | - S C Baraban
- Department of Neurological Surgery and Weill Institute for Neuroscience, University of California, San Francisco, San Francisco, CA, USA
| | - M P Richardson
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - M P Meyer
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - R E Rosch
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
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85
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Ellis CA, Berkovic SF, Epstein MP, Ottman R. The "maternal effect" on epilepsy risk: Analysis of familial epilepsies and reassessment of prior evidence. Ann Neurol 2020; 87:132-138. [PMID: 31637767 PMCID: PMC7147955 DOI: 10.1002/ana.25625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 09/22/2019] [Accepted: 10/18/2019] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Previous studies have observed that epilepsy risk is higher among offspring of affected women than offspring of affected men. We tested whether this "maternal effect" was present in familial epilepsies, which are enriched for genetic factors that contribute to epilepsy risk. METHODS We assessed evidence of a maternal effect in a cohort of families containing ≥3 persons with epilepsy using 3 methods: (1) "downward-looking" analysis, comparing the rate of epilepsy in offspring of affected women versus men; (2) "upward-looking" analysis, comparing the rate of epilepsy among mothers versus fathers of affected individuals; and (3) lineage analysis, comparing the proportion of affected individuals with family history of epilepsy on the maternal versus paternal side. RESULTS Downward-looking analysis revealed no difference in epilepsy rates among offspring of affected mothers versus fathers (prevalence ratio = 1.0, 95% confidence interval [CI] = 0.8-1.2). Upward-looking analysis revealed more affected mothers than affected fathers; this effect was similar for affected and unaffected sibships (odds ratio = 0.8, 95% CI = 0.5-1.2) and was explained by a combination of differential fertility and participation rates. Lineage analysis revealed no significant difference in the likelihood of maternal versus paternal family history of epilepsy. INTERPRETATION We found no evidence of a maternal effect on epilepsy risk in this familial epilepsy cohort. Confounding sex imbalances can create the appearance of a maternal effect in upward-looking analyses and may have impacted prior studies. We discuss possible explanations for the lack of evidence, in familial epilepsies, of the maternal effect observed in population-based studies. ANN NEUROL 2020;87:132-138.
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Affiliation(s)
- Colin A Ellis
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, Victoria, Australia
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | | | - Ruth Ottman
- Departments of Epidemiology and Neurology, and the G. H. Sergievsky Center, Columbia University, New York, NY
- Division of Translational Epidemiology, New York State Psychiatric Institute, New York, NY
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Höller Y, Höhn C, Schwimmbeck F, Plancher G, Trinka E. Effects of Antiepileptic Drug Tapering on Episodic Memory as Measured by Virtual Reality Tests. Front Neurol 2020; 11:93. [PMID: 32153492 PMCID: PMC7045343 DOI: 10.3389/fneur.2020.00093] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/27/2020] [Indexed: 11/17/2022] Open
Abstract
Antiepileptic drugs impair episodic memory in patients with epilepsy, but this effect has so far only been examined with tests that do not provide first-person experience-an aspect that is crucial for episodic memory. Virtual reality techniques facilitate the development of ecologically valid tests. In the present study, we measure the effect of antiepileptic drug changes in a within-subject design using a virtual reality test in order to provide direct evidence for effects of antiepileptic drugs on episodic memory. Among 106 recruited patients, 97 participated in a virtual reality test up to six times during a 4-day hospitalization, and 78 patients underwent changes in drug load during this period. There were six parallel versions of a virtual town test, with immediate recall and delayed recall after about 12 h. The test requires recall of elements, details, sequence of experience, and egocentric and allocentric spatial memory. We determined drug load by defined daily dose, and compared test performance at lowest antiepileptic drug load to highest antiepileptic drug load. Across the six towns, performance was lower in delayed compared to immediate recall. There was an overall effect of medication when comparing patients taking vs. not taking antiepileptic drugs and/or psychoactive drugs (p = 0.005). Furthermore, there was a within-subject effect of antiepileptic drug load (p = 0.01), indicating lower test performance at higher drug load. There was no effect of gender, daytime, circadian type, depression, seizures, lesions, and epilepsy. For patients with temporal lobe epilepsy, there was no effect of lateralization. The present study provides direct evidence for episodic memory impairment due to antiepileptic drugs, suggesting that a small change in drug load can matter. This study can serve as a proof of principle for the methodology, but a larger sample is needed to examine the differential effects of individual antiepileptic drugs.
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Affiliation(s)
- Yvonne Höller
- Faculty of Psychology, University of Akureyri, Akureyri, Iceland.,Department of Neurology, Christian Doppler Medical Centre and Centre for Cognitive Neuroscience, Paracelsus Medical University, Salzburg, Austria
| | - Christopher Höhn
- Department of Neurology, Christian Doppler Medical Centre and Centre for Cognitive Neuroscience, Paracelsus Medical University, Salzburg, Austria.,Department of Psychology, University of Salzburg, Salzburg, Austria
| | - Fabian Schwimmbeck
- Department of Neurology, Christian Doppler Medical Centre and Centre for Cognitive Neuroscience, Paracelsus Medical University, Salzburg, Austria.,Department of Psychology, University of Salzburg, Salzburg, Austria
| | - Gaën Plancher
- Laboratoire EMC, Mémoire, Émotion et Action, Université Lumiére Lyon 2, Lyon, France
| | - Eugen Trinka
- Department of Neurology, Christian Doppler Medical Centre and Centre for Cognitive Neuroscience, Paracelsus Medical University, Salzburg, Austria
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87
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Kang KW, Kim W, Cho YW, Lee SK, Jung KY, Shin W, Kim DW, Kim WJ, Lee HW, Kim W, Kim K, Lee SH, Choi SY, Kim MK. Genetic characteristics of non-familial epilepsy. PeerJ 2019; 7:e8278. [PMID: 31875159 PMCID: PMC6925949 DOI: 10.7717/peerj.8278] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 11/22/2019] [Indexed: 12/25/2022] Open
Abstract
Background Knowledge of the genetic etiology of epilepsy can provide essential prognostic information and influence decisions regarding treatment and management, leading us into the era of precision medicine. However, the genetic basis underlying epileptogenesis or epilepsy pharmacoresistance is not well-understood, particularly in non-familial epilepsies with heterogeneous phenotypes that last until or start in adulthood. Methods We sought to determine the contribution of known epilepsy-associated genes (EAGs) to the causation of non-familial epilepsies with heterogeneous phenotypes and to the genetic basis underlying epilepsy pharmacoresistance. We performed a multi-center study for whole exome sequencing-based screening of 178 selected EAGs in 243 non-familial adult patients with primarily focal epilepsy (122 drug-resistant and 121 drug-responsive epilepsies). The pathogenicity of each variant was assessed through a customized stringent filtering process and classified according to the American College of Medical Genetics and Genomics guidelines. Results Possible causal genetic variants of epilepsy were uncovered in 13.2% of non-familial patients with primarily focal epilepsy. The diagnostic yield according to the seizure onset age was 25% (2/8) in the neonatal and infantile period, 11.1% (14/126) in childhood and 14.7% (16/109) in adulthood. The higher diagnostic yields were from ion channel-related genes and mTOR pathway-related genes, which does not significantly differ from the results of previous studies on familial or early-onset epilepsies. These potentially pathogenic variants, which were identified in genes that have been mainly associated with early-onset epilepsies with severe phenotypes, were also linked to epilepsies that start in or last until adulthood in this study. This finding suggested the presence of one or more disease-modifying factors that regulate the onset time or severity of epileptogenesis. The target hypothesis of epilepsy pharmacoresistance was not verified in our study. Instead, neurodevelopment-associated epilepsy genes, such as TSC2 or RELN, or structural brain lesions were more strongly associated with epilepsy pharmacoresistance. Conclusions We revealed a fraction of possible causal genetic variants of non-familial epilepsies in which genetic testing is usually overlooked. In this study, we highlight the importance of earlier identification of the genetic etiology of non-familial epilepsies, which leads us to the best treatment options in terms of precision medicine and to future neurobiological research for novel drug development. This should be considered a justification for physicians determining the hidden genetics of non-familial epilepsies that last until or start in adulthood.
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Affiliation(s)
- Kyung Wook Kang
- Department of Neurology, Chonnam National University Medical School, Gwangju, South Korea
| | - Wonkuk Kim
- Department of Applied Statistics, Chung-Ang University, Seoul, South Korea
| | - Yong Won Cho
- Department of Neurology, Keimyung University Dongsan Medical Center, Daegu, South Korea
| | - Sang Kun Lee
- Department of Neurology, Seoul National University Hospital, Seoul, South Korea
| | - Ki-Young Jung
- Department of Neurology, Seoul National University Hospital, Seoul, South Korea
| | - Wonchul Shin
- Department of Neurology, Kyung Hee University Hospital at Gangdong, Seoul, South Korea
| | - Dong Wook Kim
- Department of Neurology, Konkuk University School of Medicine, Seoul, South Korea
| | - Won-Joo Kim
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Hyang Woon Lee
- Department of Neurology, Ewha Womans University School of Medicine and Ewha Medical Research Institute, Seoul, South Korea
| | - Woojun Kim
- Department of Neurology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Keuntae Kim
- Department of Neurology, Keimyung University Dongsan Medical Center, Daegu, South Korea
| | - So-Hyun Lee
- Department of Biomedical Science, Chonnam National University Medical School, Gwangju, South Korea
| | - Seok-Yong Choi
- Department of Biomedical Science, Chonnam National University Medical School, Gwangju, South Korea
| | - Myeong-Kyu Kim
- Department of Neurology, Chonnam National University Medical School, Gwangju, South Korea
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Abstract
PURPOSE OF REVIEW The classification of seizures, epilepsies, and epilepsy syndromes creates a framework for clinicians, researchers, and patients and their families. This classification has evolved over the years, and in 2017 the International League Against Epilepsy (ILAE) published an operational classification of seizures and epilepsies. Understanding this classification is important in the diagnosis, treatment, and understanding of seizures and epilepsies, including epilepsy incidence. RECENT FINDINGS The 2017 ILAE classification system builds on newly formulated definitions of seizures and epilepsy. Seizure classification begins by determining whether the initial manifestations of the seizure are focal or generalized. If the onset of the seizure is missed or unclear, the seizure is of unknown onset. Focal seizures are classified according to the individual's level of awareness, the most prominent motor or nonmotor features of the seizure, and whether the focal seizure evolves to a bilateral tonic-clonic seizure. Similarly, generalized seizures are classified according to motor or nonmotor manifestations. Motor seizures are either tonic-clonic or other motor seizures. Nonmotor generalized seizures primarily refer to absence seizures. Similar to seizure classification, the epilepsies can be classified as focal or generalized. In addition, the new classification system recognizes two new categories: combined generalized and focal epilepsy and unknown epilepsy. The concept of an epilepsy syndrome has been introduced under the new classification system and refers to a cluster of features incorporating seizure types, EEG, imaging, and other features including genetics. The new classification system emphasizes the etiology of seizures and epilepsies. SUMMARY The recent ILAE seizure and epilepsy classification system aims to create a framework to better classify seizures and the epilepsies. Universal adoption and implementation of this system will enable patients, their families, clinicians, and researchers to better define and treat the epilepsies. Incidence studies have not generally classified seizures and the epilepsies, and use of this classification system, which emphasizes etiology, will lead to a better understanding of epilepsy incidence.
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89
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Liao M, Kundap U, Rosch RE, Burrows DRW, Meyer MP, Ouled Amar Bencheikh B, Cossette P, Samarut É. Targeted knockout of GABA-A receptor gamma 2 subunit provokes transient light-induced reflex seizures in zebrafish larvae. Dis Model Mech 2019; 12:dmm.040782. [PMID: 31582559 PMCID: PMC6899022 DOI: 10.1242/dmm.040782] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 09/24/2019] [Indexed: 12/29/2022] Open
Abstract
Epilepsy is a common primary neurological disorder characterized by the chronic tendency of a patient to experience epileptic seizures, which are abnormal body movements or cognitive states that result from excessive, hypersynchronous brain activity. Epilepsy has been found to have numerous etiologies and, although about two-thirds of epilepsies were classically considered idiopathic, the majority of those are now believed to be of genetic origin. Mutations in genes involved in gamma-aminobutyric acid (GABA)-mediated inhibitory neurotransmission have been associated with a broad range of epilepsy syndromes. Mutations in the GABA-A receptor gamma 2 subunit gene (GABRG2), for example, have been associated with absence epilepsy and febrile seizures in humans. Several rodent models of GABRG2 loss of function depict clinical features of the disease; however, alternative genetic models more amenable for the study of ictogenesis and for high-throughput screening purposes are still needed. In this context, we generated a gabrg2 knockout (KO) zebrafish model (which we called R23X) that displayed light/dark-induced reflex seizures. Through high-resolution in vivo calcium imaging of the brain, we showed that this phenotype is associated with widespread increases in neuronal activity that can be effectively alleviated by the anti-epileptic drug valproic acid. Moreover, these seizures only occur at the larval stages but disappear after 1 week of age. Interestingly, our whole-transcriptome analysis showed that gabrg2 KO does not alter the expression of genes in the larval brain. As a result, the gabrg2−/− zebrafish is a novel in vivo genetic model of early epilepsies that opens new doors to investigate ictogenesis and for further drug-screening assays. Summary: The authors present a novel in vivo genetic model of idiopathic epilepsy in zebrafish (gabrg2−/−) to aid the study of ictogenesis and provide a convenient genetic tool for drug screening.
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Affiliation(s)
- Meijiang Liao
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Uday Kundap
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Richard E Rosch
- Department for Developmental Neurobiology, MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK.,Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| | - Dominic R W Burrows
- Department for Developmental Neurobiology, MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Martin P Meyer
- Department for Developmental Neurobiology, MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK.,Department for Developmental Neurobiology, Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Bouchra Ouled Amar Bencheikh
- Montreal Neurological Institute and Hospital, McGill University, Montréal, QC H3A 2B4, Canada.,Neuroscience Department, Centre de Recherche, Centre Hospitalier de l'Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Patrick Cossette
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Éric Samarut
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada .,Modelis Inc., Montréal, QC H2X 0A9, Canada
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90
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Hansen TF, Møller RS. The first step towards personalized risk prediction for common epilepsies. Brain 2019; 142:3316-3318. [PMID: 31665751 DOI: 10.1093/brain/awz318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This scientific commentary refers to ‘Polygenic burden in focal and generalized epilepsies’, by Leu et al. (doi:10.1093/brain/awz292).
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Affiliation(s)
- Thomas F Hansen
- Danish Headache Center, Rigshospitalet Glostrup, Glostrup, Denmark.,Center for Protein Research, Københavns Universitet Sundhedsvidenskabelige Fakultet, København, Denmark
| | - Rikke S Møller
- Danish Epilepsy Centre, Filadelfia, Dianalund, Denmark.,Department of Regional Health Services, University of Southern Denmark, Odense, Denmark
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91
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Abstract
Abstract:Background:Epilepsy is a common neurological condition that shows a marked genetic predisposition. The advent of next-generation sequencing (NGS) has transformed clinical genetic testing by allowing the rapid screen for causative variants in multiple genes. There are currently no NGS-based multigene panel diagnostic tests available for epilepsy as a licensed clinical diagnostic test in Ontario, Canada. Eligible patient samples are sent out of country for testing by commercial laboratories, which incurs significant cost to the public healthcare system.Objective:An expert Working Group of medical geneticists, pediatric neurologists/epileptologists, biochemical geneticists, and clinical molecular geneticists from Ontario was formed by the Laboratories and Genetics Branch of the Ontario Ministry of Health and Long-Term Care to develop a programmatic approach to implementing epilepsy panel testing as a provincial service.Results:The Working Group made several recommendations for testing to support the clinical delivery of care in Ontario. First, an extension of community healthcare outcomes-based program should be incorporated to inform and educate ordering providers when requesting and interpreting a genetic panel test. Second, any gene panel testing must be “evidence-based” and takes into account varied clinical indications to reduce the chance of uncertain and secondary results. Finally, an ongoing evaluative process was recommended to ensure continued test improvement for the future.Conclusion:This epilepsy panel testing implementation plan will be a model for genetic care directed toward a specific set of conditions in the province and serve as a prototype for genetic testing for other genetically heterogeneous diseases.
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Dawson RE, Nieto Guil AF, Robertson LJ, Piltz SG, Hughes JN, Thomas PQ. Functional screening of GATOR1 complex variants reveals a role for mTORC1 deregulation in FCD and focal epilepsy. Neurobiol Dis 2019; 134:104640. [PMID: 31639411 DOI: 10.1016/j.nbd.2019.104640] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 10/07/2019] [Accepted: 10/13/2019] [Indexed: 12/20/2022] Open
Abstract
Mutations in the GAP activity toward RAGs 1 (GATOR1) complex genes (DEPDC5, NPRL2 and NPRL3) have been associated with focal epilepsy and focal cortical dysplasia (FCD). GATOR1 functions as an inhibitor of the mTORC1 signalling pathway, indicating that the downstream effects of mTORC1 deregulation underpin the disease. However, the vast majority of putative disease-causing variants have not been functionally assessed for mTORC1 repression activity. Here, we develop a novel in vitro functional assay that enables rapid assessment of GATOR1-gene variants. Surprisingly, of the 17 variants tested, we show that only six showed significantly impaired mTORC1 inhibition. To further investigate variant function in vivo, we generated a conditional Depdc5 mouse which modelled a 'second-hit' mechanism of disease. Generation of Depdc5 null 'clones' in the embryonic brain resulted in mTORC1 hyperactivity and modelled epilepsy and FCD symptoms including large dysmorphic neurons, defective migration and lower seizure thresholds. Using this model, we validated DEPDC5 variant F164del to be loss-of-function. We also show that Q542P is not functionally compromised in vivo, consistent with our in vitro findings. Overall, our data show that mTORC1 deregulation is the central pathological mechanism for GATOR1 variants and also indicates that a significant proportion of putative disease variants are pathologically inert, highlighting the importance of GATOR1 variant functional assessment.
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Affiliation(s)
- Ruby E Dawson
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Alvaro F Nieto Guil
- School of Medicine, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Louise J Robertson
- School of Medicine, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Sandra G Piltz
- School of Medicine, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - James N Hughes
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Paul Q Thomas
- School of Medicine, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia; Precision Medicine Theme, South Australia Health and Medical Research Institute, Adelaide, SA 5000, Australia.
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93
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Lybrand ZR, Goswami S, Hsieh J. Stem cells: A path towards improved epilepsy therapies. Neuropharmacology 2019; 168:107781. [PMID: 31539537 DOI: 10.1016/j.neuropharm.2019.107781] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 12/12/2022]
Abstract
Despite the immense growth of new anti-seizure drugs (ASDs), approximately one-third of epilepsy patients remain resistant to current treatment options. Advancements in whole genome sequencing technology continues to identify an increasing number of epilepsy-associated genes at a rate that is outpacing the development of in vivo animal models. Patient-derived induced pluripotent stem cells (iPSCs) show promise in providing a platform for modeling genetic epilepsies, high throughput drug screening, and personalized medicine. This is largely due to the ease of collecting donor cells for iPSC reprogramming, and their ability to be maintained in vitro, while preserving the patient's genetic background. In this review, we summarize the current state of iPSC research in epilepsy and closely related syndromes, discuss the growing need for high-throughput drug screening (HTS), and review the use of stem cell technology for the purpose of autologous transplantation for epilepsy stem cell therapy. Although the use of iPSC technology, as it applies to ASD discovery, is in its infancy, we highlight the significant progress that has been made in phenotype and assay development to facilitate systematic HTS for personalized medicine. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.
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Affiliation(s)
- Zane R Lybrand
- Department of Biology and Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Sonal Goswami
- Department of Biology and Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Jenny Hsieh
- Department of Biology and Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA.
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94
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Ellis CA, Petrovski S, Berkovic SF. Epilepsy genetics: clinical impacts and biological insights. Lancet Neurol 2019; 19:93-100. [PMID: 31494011 DOI: 10.1016/s1474-4422(19)30269-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 05/18/2019] [Accepted: 06/11/2019] [Indexed: 01/23/2023]
Abstract
Genomics now has an increasingly important role in neurology clinics. Regarding the epilepsies, innovations centred around technology, analytics, and collaboration have led to remarkable progress in gene discovery and have revealed the diverse array of genetic mechanisms and neurobiological pathways that contribute to these disorders. The new genomic era can present a challenge to clinicians, who now find themselves asked to interpret and apply genetic data to their daily management of patients with epilepsy. Navigation of this new era will require genetic literacy and familiarity with research advances in epilepsy genetics. Genetic epilepsy diagnoses now directly affect clinical care, and their importance will only increase as new targeted treatments continue to emerge. At the same time, new genetic insights challenge us to move from a deterministic view of genetic changes to a more nuanced appreciation of genetic risk within complex neurobiological systems that give rise to epilepsy.
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Affiliation(s)
- Colin A Ellis
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA; Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, VIC, Australia
| | - Slavé Petrovski
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, VIC, Australia; Centre for Genomics Research, Discovery Sciences, Research and Development Biopharmaceuticals, AstraZeneca, Cambridge, UK
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, VIC, Australia.
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95
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Kirchner A, Dachet F, Loeb JA. Identifying targets for preventing epilepsy using systems biology of the human brain. Neuropharmacology 2019; 168:107757. [PMID: 31493467 DOI: 10.1016/j.neuropharm.2019.107757] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 08/30/2019] [Accepted: 09/02/2019] [Indexed: 12/13/2022]
Abstract
Approximately one third of all epilepsy patients are resistant to current therapeutic treatments. Some patients with focal forms of epilepsy benefit from invasive surgical approaches that can lead to large surgical resections of human epileptic neocortex. We have developed a systems biology approach to take full advantage of these resections and the brain tissues they generate as a means to understand underlying mechanisms of neocortical epilepsy and to identify novel biomarkers and therapeutic targets. In this review, we will describe our unique approach that has led to the development of a 'NeuroRepository' of electrically-mapped epileptic tissues and associated data. This 'Big Data' approach links quantitative measures of ictal and interictal activities corresponding to a specific intracranial electrode to clinical, imaging, histological, genomic, proteomic, and metabolomic measures. This highly characterized data and tissue bank has given us an extraordinary opportunity to explore the underlying electrical, cellular, and molecular mechanisms of the human epileptic brain. We describe specific examples of how an experimental design that compares multiple cortical regions with different electrical activities has led to discoveries of layer-specific pathways and how these can be 'reverse translated' from animal models back to humans in the form of new biomarkers and therapeutic targets. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.
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Affiliation(s)
- Allison Kirchner
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Fabien Dachet
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL, 60612, USA; University of Illinois Neuro Repository, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Jeffrey A Loeb
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL, 60612, USA; University of Illinois Neuro Repository, University of Illinois at Chicago, Chicago, IL, 60612, USA.
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96
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Truty R, Patil N, Sankar R, Sullivan J, Millichap J, Carvill G, Entezam A, Esplin ED, Fuller A, Hogue M, Johnson B, Khouzam A, Kobayashi Y, Lewis R, Nykamp K, Riethmaier D, Westbrook J, Zeman M, Nussbaum RL, Aradhya S. Possible precision medicine implications from genetic testing using combined detection of sequence and intragenic copy number variants in a large cohort with childhood epilepsy. Epilepsia Open 2019; 4:397-408. [PMID: 31440721 PMCID: PMC6698688 DOI: 10.1002/epi4.12348] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 05/19/2019] [Accepted: 05/31/2019] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE Molecular genetic etiologies in epilepsy have become better understood in recent years, creating important opportunities for precision medicine. Building on these advances, detailed studies of the complexities and outcomes of genetic testing for epilepsy can provide useful insights that inform and refine diagnostic approaches and illuminate the potential for precision medicine in epilepsy. METHODS We used a multi-gene next-generation sequencing (NGS) panel with simultaneous sequence and exonic copy number variant detection to investigate up to 183 epilepsy-related genes in 9769 individuals. Clinical variant interpretation was performed using a semi-quantitative scoring system based on existing professional practice guidelines. RESULTS Molecular genetic testing provided a diagnosis in 14.9%-24.4% of individuals with epilepsy, depending on the NGS panel used. More than half of these diagnoses were in children younger than 5 years. Notably, the testing had possible precision medicine implications in 33% of individuals who received definitive diagnostic results. Only 30 genes provided 80% of molecular diagnoses. While most clinically significant findings were single-nucleotide variants, ~15% were other types that are often challenging to detect with traditional methods. In addition to clinically significant variants, there were many others that initially had uncertain significance; reclassification of 1612 such variants with parental testing or other evidence contributed to 18.5% of diagnostic results overall and 6.1% of results with precision medicine implications. SIGNIFICANCE Using an NGS gene panel with key high-yield genes and robust analytic sensitivity as a first-tier test early in the diagnostic process, especially for children younger than 5 years, can possibly enable precision medicine approaches in a significant number of individuals with epilepsy.
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Affiliation(s)
| | - Nila Patil
- Departments of Pediatrics and NeurologyUniversity of California Los AngelesLos AngelesCalifornia
| | - Raman Sankar
- Departments of Pediatrics and NeurologyUniversity of California Los AngelesLos AngelesCalifornia
| | - Joseph Sullivan
- Pediatric Epilepsy CenterUniversity of California San FranciscoSan FranciscoCalifornia
| | - John Millichap
- Lurie Children's Hospital and Northwestern UniversityChicagoIllinois
| | - Gemma Carvill
- Ken and Ruth Davee Department of NeurologyNorthwestern UniversityChicagoIllinois
| | | | | | | | | | | | | | | | | | | | | | | | | | - Robert L. Nussbaum
- InvitaeSan FranciscoCalifornia
- Volunteer FacultyUniversity of California San FranciscoSan FranciscoCalifornia
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97
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Leung WL, Casillas-Espinosa P, Sharma P, Perucca P, Powell K, O'Brien TJ, Semple BD. An animal model of genetic predisposition to develop acquired epileptogenesis: The FAST and SLOW rats. Epilepsia 2019; 60:2023-2036. [PMID: 31468516 DOI: 10.1111/epi.16329] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 08/06/2019] [Accepted: 08/06/2019] [Indexed: 12/12/2022]
Abstract
Epidemiological data and gene association studies suggest a genetic predisposition to developing epilepsy after an acquired brain insult, such as traumatic brain injury. An improved understanding of genetic determinants of vulnerability is imperative for early disease diagnosis and prognosis prediction, with flow-on benefits for the development of targeted antiepileptogenic treatments as well as optimal clinical trial design. In the laboratory, one approach to investigate why some individuals are more vulnerable to acquired epilepsy than others is to examine unique rodent models exhibiting either vulnerability or resistance to epileptogenesis. This review focuses on the most well-characterized of these models, the FAST (seizure-prone) and SLOW (seizure-resistant) rat strains, which were derived by selective breeding for differential amygdala electrical kindling rates. We describe how these strains differ in their seizure profiles, neuroanatomy, and neurobehavioral phenotypes, both at baseline and after a brain insult, with this knowledge proving fruitful to identify common pathological abnormalities associated with seizure susceptibility and psychiatric comorbidities. It is important to note that accruing data on strain differences in multiple biological processes provides insight into why some individuals may be more vulnerable to epileptogenesis, although future studies are evidently needed to identify the precise molecular and genetic risk factors. Together, the FAST and SLOW rat strains, and other similar experimental models, are invaluable neurobiological tools to investigate the effect of genetic background on acquired epilepsy risk, as well as the poorly understood relationship between epilepsy development and associated comorbidities.
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Affiliation(s)
- Wai Lam Leung
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Vic., Australia
| | - Pablo Casillas-Espinosa
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Vic., Australia.,Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Parkville, Vic., Australia
| | - Pragati Sharma
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Vic., Australia.,Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Parkville, Vic., Australia.,Department of Neurology, Alfred Health, Melbourne, Vic., Australia
| | - Piero Perucca
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Vic., Australia.,Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Parkville, Vic., Australia.,Department of Neurology, Alfred Health, Melbourne, Vic., Australia.,Department of Neurology, Royal Melbourne Hospital, Parkville, Vic., Australia
| | - Kim Powell
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Vic., Australia.,Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Parkville, Vic., Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Vic., Australia.,Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Parkville, Vic., Australia.,Department of Neurology, Alfred Health, Melbourne, Vic., Australia.,Department of Neurology, Royal Melbourne Hospital, Parkville, Vic., Australia
| | - Bridgette D Semple
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Vic., Australia.,Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Parkville, Vic., Australia
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98
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Helbig I, Riggs ER, Barry CA, Klein KM, Dyment D, Thaxton C, Sadikovic B, Sands TT, Wagnon JL, Liaquat K, Cilio MR, Mirzaa G, Park K, Axeen E, Butler E, Bardakjian TM, Striano P, Poduri A, Siegert RK, Grant AR, Helbig KL, Mefford HC. The ClinGen Epilepsy Gene Curation Expert Panel-Bridging the divide between clinical domain knowledge and formal gene curation criteria. Hum Mutat 2019; 39:1476-1484. [PMID: 30311377 DOI: 10.1002/humu.23632] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 08/01/2018] [Accepted: 08/28/2018] [Indexed: 01/03/2023]
Abstract
The field of epilepsy genetics is advancing rapidly and epilepsy is emerging as a frequent indication for diagnostic genetic testing. Within the larger ClinGen framework, the ClinGen Epilepsy Gene Curation Expert Panel is tasked with connecting two increasingly separate fields: the domain of traditional clinical epileptology, with its own established language and classification criteria, and the rapidly evolving area of diagnostic genetic testing that adheres to formal criteria for gene and variant curation. We identify critical components unique to the epilepsy gene curation effort, including: (a) precise phenotype definitions within existing disease and phenotype ontologies; (b) consideration of when epilepsy should be curated as a distinct disease entity; (c) strategies for gene selection; and (d) emerging rules for evaluating functional models for seizure disorders. Given that de novo variants play a prominent role in many of the epilepsies, sufficient genetic evidence is often awarded early in the curation process. Therefore, the emphasis of gene curation is frequently shifted toward an iterative precuration process to better capture phenotypic associations. We demonstrate that within the spectrum of neurodevelopmental disorders, gene curation for epilepsy-associated genes is feasible and suggest epilepsy-specific conventions, laying the groundwork for a curation process of all major epilepsy-associated genes.
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Affiliation(s)
- Ingo Helbig
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Department of Neuropediatrics, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Erin Rooney Riggs
- Autism & Developmental Medicine Institute, Geisinger Health System, Lewisburg, Pennsylvania, USA
| | - Carrie-Anne Barry
- Autism & Developmental Medicine Institute, Geisinger Health System, Lewisburg, Pennsylvania, USA
| | - Karl Martin Klein
- Department of Neurology, Epilepsy Center Frankfurt Rhine-Main, Goethe University, Frankfurt am Main, Frankfurt, Germany.,Department of Neurology, Epilepsy Center Hessen, Philipps University, Marburg, Marburg, Germany
| | - David Dyment
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - Courtney Thaxton
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Bekim Sadikovic
- Department of Pathology and Laboratory Medicine, Western University Molecular Genetic Laboratory, London Health Sciences, London, Ontario, Canada
| | - Tristan T Sands
- Division of Child Neurology, Columbia University Medical Center, New York, New York, USA
| | - Jacy L Wagnon
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Khalida Liaquat
- Quest Diagnostics, Athena Diagnostics, Marlborough, Massachusetts, USA
| | - Maria Roberta Cilio
- Departments of Pediatrics and Neurology, University of California, San Francisco, California, USA
| | - Ghayda Mirzaa
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, USA.,Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Kristen Park
- Department of Pediatrics and Neurology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Erika Axeen
- Department of Neurology, University of Virginia, Charlottesville, Virginia, USA
| | | | - Tanya M Bardakjian
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, DINOGMI-Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, "G. Gaslini" Institute, University of Genoa, Genova, Italy
| | - Annapurna Poduri
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Rebecca K Siegert
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts, USA
| | - Andrew R Grant
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts, USA
| | - Katherine L Helbig
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Heather C Mefford
- Division of Genetic Medicine, University of Washington, Seattle, Washington, USA
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99
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Gan J, Cai Q, Galer P, Ma D, Chen X, Huang J, Bao S, Luo R. Mapping the knowledge structure and trends of epilepsy genetics over the past decade: A co-word analysis based on medical subject headings terms. Medicine (Baltimore) 2019; 98:e16782. [PMID: 31393404 PMCID: PMC6709143 DOI: 10.1097/md.0000000000016782] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
INTRODUCTION Over the past 10 years, epilepsy genetics has made dramatic progress. This study aimed to analyze the knowledge structure and the advancement of epilepsy genetics over the past decade based on co-word analysis of medical subject headings (MeSH) terms. METHODS Scientific publications focusing on epilepsy genetics from the PubMed database (January 2009-December 2018) were retrieved. Bibliometric information was analyzed quantitatively using Bibliographic Item Co-Occurrence Matrix Builder (BICOMB) software. A knowledge social network analysis and publication trend based on the high-frequency MeSH terms was built using VOSviewer. RESULTS According to the search strategy, a total of 5185 papers were included. Among all the extracted MeSH terms, 86 high-frequency MeSH terms were identified. Hot spots were clustered into 5 categories including: "ion channel diseases," "beyond ion channel diseases," "experimental research & epigenetics," "single nucleotide polymorphism & pharmacogenetics," and "genetic techniques". "Epilepsy," "mutation," and "seizures," were located at the center of the knowledge network. "Ion channel diseases" are typically in the most prominent position of epilepsy genetics research. "Beyond ion channel diseases" and "genetic techniques," however, have gradually grown into research cores and trends, such as "intellectual disability," "infantile spasms," "phenotype," "exome," " deoxyribonucleic acid (DNA) copy number variations," and "application of next-generation sequencing." While ion channel genes such as "SCN1A," "KCNQ2," "SCN2A," "SCN8A" accounted for nearly half of epilepsy genes in MeSH terms, a number of additional beyond ion channel genes like "CDKL5," "STXBP1," "PCDH19," "PRRT2," "LGI1," "ALDH7A1," "MECP2," "EPM2A," "ARX," "SLC2A1," and more were becoming increasingly popular. In contrast, gene therapies, treatment outcome, and genotype-phenotype correlations were still in their early stages of research. CONCLUSION This co-word analysis provides an overview of epilepsy genetics research over the past decade. The 5 research categories display publication hot spots and trends in epilepsy genetics research which could consequently supply some direction for geneticists and epileptologists when launching new projects.
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Affiliation(s)
- Jing Gan
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University) Ministry of Education, China
| | - Qianyun Cai
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University) Ministry of Education, China
| | - Peter Galer
- Department of Biomedical and Health Informatics, The Children's Hospital of Philadelphia, PA
| | - Dan Ma
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu
| | - Xiaolu Chen
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu
| | - Jichong Huang
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University) Ministry of Education, China
| | - Shan Bao
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University) Ministry of Education, China
| | - Rong Luo
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu
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100
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Punetha J, Karaca E, Gezdirici A, Lamont RE, Pehlivan D, Marafi D, Appendino JP, Hunter JV, Akdemir ZC, Fatih JM, Jhangiani SN, Gibbs RA, Innes AM, Posey JE, Lupski JR. Biallelic CACNA2D2 variants in epileptic encephalopathy and cerebellar atrophy. Ann Clin Transl Neurol 2019; 6:1395-1406. [PMID: 31402629 PMCID: PMC6689679 DOI: 10.1002/acn3.50824] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/29/2019] [Accepted: 05/29/2019] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE To characterize the molecular and clinical phenotypic basis of developmental and epileptic encephalopathies caused by rare biallelic variants in CACNA2D2. METHODS Two affected individuals from a family with clinical features of early onset epileptic encephalopathy were recruited for exome sequencing at the Centers for Mendelian Genomics to identify their molecular diagnosis. GeneMatcher facilitated identification of a second family with a shared candidate disease gene identified through clinical gene panel-based testing. RESULTS Rare biallelic CACNA2D2 variants have been previously reported in three families with developmental and epileptic encephalopathy, and one family with congenital ataxia. We identified three individuals in two unrelated families with novel homozygous rare variants in CACNA2D2 with clinical features of developmental and epileptic encephalopathy and cerebellar atrophy. Family 1 includes two affected siblings with a likely damaging homozygous rare missense variant c.1778G>C; p.(Arg593Pro) in CACNA2D2. Family 2 includes a proband with a homozygous rare nonsense variant c.485_486del; p.(Tyr162Ter) in CACNA2D2. We compared clinical and molecular findings from all nine individuals reported to date and note that cerebellar atrophy is shared among all. INTERPRETATION Our study supports the candidacy of CACNA2D2 as a disease gene associated with a phenotypic spectrum of neurological disease that include features of developmental and epileptic encephalopathy, ataxia, and cerebellar atrophy. Age at presentation may affect apparent penetrance of neurogenetic trait manifestations and of a particular clinical neurological endophenotype, for example, seizures or ataxia.
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Affiliation(s)
- Jaya Punetha
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Ender Karaca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Alper Gezdirici
- Department of Medical Genetics, Kanuni Sultan Suleyman Training and Research Hospital, Istanbul, Turkey
| | - Ryan E Lamont
- Department of Medical Genetics, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Dana Marafi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Juan P Appendino
- Clinical Neuroscience, Department of Pediatrics, Alberta Children's Hospital, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jill V Hunter
- Department of Radiology, Texas Children's Hospital, Houston, Texas
| | - Zeynep C Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Jawid M Fatih
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | | | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas
| | - A Micheil Innes
- Department of Medical Genetics, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Pediatrics, Cumming School of Medicine, Alberta Children's Hospital, University of Calgary, Calgary, Alberta, Canada
| | - Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas.,Texas Children's Hospital, Houston, Texas.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas
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